Does any amendment in the bill of rights take priority over any other? As far as I know, unless a contract/compact states otherwise, or a provision was added at a different point of time, every provision in the contract carries the same priority. The bill of rights was added to the constitution all at once and so each amendment carries the same priority and so when there is a conflict least restrictive means has to be applied.
Sometimes rights conflict with each other, and the courts decide which right takes priority. The Sixth Amendment provides that a defendant is entitled to "compulsory process for obtaining witnesses in his favor". The Fifth Amendment says "No person... shall be compelled in any criminal case to be a witness against himself". And the First Amendment gives the right to free speech, which includes the right to not be compelled to speak. If you're on trial and try to get someone else to confess on the stand, his Fifth Amendment right against self-incrimination trumps your Sixth Amendment right to have him testify. But if he couldn't take the fifth (for example, if he had already been acquitted), your Sixth Amendment right would override his First Amendment right to free speech.
No, under US law, it is an "executive agreement", not a "treaty". The vast majority of US's international agreements are done as executive agreements, and not treaties; and the power of the executive branch to make executive agreements has been repeatedly upheld in the courts. Specifically, there are two types of executive agreements: "Congressional-executive agreements". These are the ones that require changes to legislation to be implemented. Congress passes the needed legislation just like any other normal legislation, i.e. a majority of both houses of Congress. Most trade agreements are passed as congressional-executive agreements. "Sole executive agreements". These are the ones that do not require changes to legislation to be implemented. Congress is not involved at all. This Iran nuclear agreement is a "sole executive agreement" because it does not require Congressional action to be implemented. (So it doesn't need to be passed by a simple majority by Congress.) The President already has the legal authority to implement all of the US's obligations under the agreement, which are the relief of certain Iran sanctions. Some of those sanctions were implemented by the President, and which the President can remove by himself. Some of these sanctions were implemented by Acts of Congress, but those Acts specifically give the President the authority to waive them. The Iran Nuclear Agreement Review Act of 2015 (the "Corker bill"), passed by Congress in May 2015, also confirms that "It is the sense of Congress that: [...] this Act does not require a vote by Congress for the agreement to commence;" As to your question about whether something can "have the effect of a treaty if it's passed by a simple majority". The answer is yes (in the other way around). The Supreme Court ruled in the Head Money Cases that "treaties" (ratified by 2/3 of the Senate as specified in Article II) have the same legal effect in US law as regular legislation passed by Congress (by a simple majority of both houses), which means that Congress can modify or repeal (insofar as US law is concerned) any "treaty" that is ratified by the Senate, by passing a later law that contradicts it, just like it can with regular legislation. So, yes, any regular legislation passed by a simple majority (including for congressional-executive agreements) has the same legal effect as treaties.
No state can amend the US Constitution by itself. Technically, an amendment to the Constitution can be proposed a constitutional convention that is called for by two-thirds of the State legislatures (though this is has never happened; all 27 amendments have been proposed by the Federal Congress, which is the alternative path). This can be done without any kind of Federal approval what so ever. After proposal, an amendment must be ratified by three-fourths of state legislatures. EDIT: Regarding how to &quot;get a convention started&quot;: This hasn't been tested, since a non-Congressional amendment has not, to my knowledge, been attempted, but I would imagine a Convention would be called if 2/3rds of the states submitted requests to Congress (which would probably either be a law or a joint-resolution, which is like a law without executive approval, but the form would probably be governed by each state's respective Constitution). Alternatively, it may be sufficient for state legislatures to designate delegates who meet up somewhere (as that is essentially what happened with the Constitutional Congress, i.e. the delegates who met and drafted the US Federal Constitution). A point has been raised in another answer that there may be an issue; however, I'm not convinced of this being a bar to a Convention. The delegates at the Constitutional Congress were original chosen to discuss changes to the Articles of Confederation, but wound up throwing the whole thing out and starting from scratch instead. Therefore, I do not see calls for a convention with differing but related objectives to be a problem; the whole point of a Convention in the Constitutional Amendment process is to discuss and compromise; otherwise, why require it before skipping to the 3/4ths of states ratifying, if the 2/3rds of states already have to agree on exactly what is being proposed before sending delegates.
The comments have basically covered this, but: It's a slightly weird parallel structure ("who shall not be at least 25, and been a citizen for 7 years, and who shall not be a resident"). The Constitution is not written in fluid 21st-century English. But the obviously correct way to parse the sentence is that no one can be a representative who isn't a 25-year-old or older who's been a citizen for at least 7 years; furthermore, no one can be a representative who wasn't a resident of the state they represent when they were elected. With some parts of the Constitution (like the Second Amendment), the drafting results in actual disputes about the intended meaning. With other parts (like here), only one reading makes any sense. It's the same with the requirements to be President. The Constitution says "No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President," which could be read as "you're not eligible unless, when the Constitution was adopted, you were either a citizen of the US or a natural-born citizen." But that's a silly reading, so "at the time of the Adoption" is read as only applying to "a Citizen of the United States:" natural-born citizens are eligible period, and people who were born before the US was a thing but were citizens by the time the Constitution was adopted were grandfathered in.
Let's look at the Ur-example of a free-speech law, and the most wide-ranging, the First Amendment to the Constitution of the United States of America. It says (my emphasis): Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances. This limitation applies only to the government. Indeed, it has been argued that this limitation only applies to the legislative branch of government and not to the executive (except when exercising legislatively delegated power) or judicial branches. Certainly, the courts have held that it is within their power to issue "gag" restraining orders. Notwithstanding, it imposes no restrictions on how non-government actors can limit your free speech. The owner of a shopping centre can require you not to evangelise, the owner of a stadium can require you not to use offensive language and the owner of a social media platform can restrict your speech in any way they wish. You have a right to talk - they have a right not to give you a platform.
Generally speaking the &quot;blessings of liberty&quot; phrase from the preamble to the US Constitution is not relied on for anything. It does not grant additional power to Congress or the Federal government as a whole, neither does it restrict the Federal government beyond the restrictions already included in the body of the Constitution. Congress often accepts hearsay when it takes testimony before a committee. Such testimony need not comply with the rules of evidence that apply in court. I am not clear what you mean by &quot;to pretext privacy and the right to try&quot;, please clarify this. I am not aware of any &quot;right to try&quot; under the Federal or State governments. The word &quot;pretext&quot; is not usually used as a verb in this way. Edit The link on &quot;right to try&quot; goes to a Quora question about laws passed by Congress later being held to be unconstitutional. That does happen. but I have never herd it called &quot;the right to try&quot;. The link on &quot;pretext&quot; goes to a security.se question about a &quot;convict internet&quot;. I don't see what that has to to with the preamble to the Constitution. 2nd Edit The &quot;blessings of liberty&quot; phrase from the preamble has nothing to do with laws against discrimination, neither authorizing nor restricting such laws.
US Constitutional law generally recognizes the right of freedom of movement, e.g. in Corfield v. Coryell, 6 Fed. Cas. 546, Crandall v. Nevada, 73 U.S. 35, Paul v. Virginia, 75 U.S. 168. The more recent case Saenz v. Roe, 526 U.S. 489 affirms the position that restricting the "right to travel violates the Equal Protection Clause absent a compelling governmental interest", and one of the specific rights subsumed under the right to travel is "the right to enter and leave another State". The "compelling governmental interest" is a reference to standard of judicial review known as strict scrutiny, where a law that restricts a fundamental right (the right to travel) is required for a "compelling state interest", is "narrowly tailored" to that purpose, and is the "least restrictive means". It is highly likely that each state has a statute that grants broad powers to the governor in case of a state of emergency. Such an order would then have to be scrutinized strictly, with respect to the narrow tailoring and least restrictive aspects of the question. We would then have to analyze the specifics of the case and order.
Before getting into the technical answer to this question it is worth noting that when matters of a constitutional nature are involved then in practice it is not just a matter of a technical &quot;legal&quot; answer. Students and academics like to pose hypothetical questions such as &quot;What would happen if the Queen refused assent to a Bill?&quot; or &quot;If Parliament is supreme, could it abolish the courts?&quot; etc. The practical reality is that a liberal democracy, such as ours, ultimately relies on those in positions of power to respect the democratic conventions and preserve the constitution. When there is a legal angle to some constitutional issue the courts will play their part but, whatever legal analysis their judgments may contain, they will always have in mind the importance of maintaining our democratic system. It is also worth noting that where an Act contains an &quot;ouster&quot; clause (saying that a certificate of X shall not be questioned in any court of law) the courts always find a way to interpret that so that it does not apply in any case where the courts think they should adjudicate! Those preliminaries out of the way, I think the technical legal answer to your question is that first of all the Speaker decides and provides a certificate under s.2(2). You will see that s.2(1) deals with &quot;any other bill&quot; (your third bullet point) and s.2(2) requires a certificate from the Speaker that &quot;the provisions of this section have been duly complied with&quot; (i.e. that it is indeed in the &quot;any other bill&quot; category). Of course there is a further question of whether, if the Speaker gets it wrong, the courts could intervene and exactly how that might happen (the so-called &quot;John Bercow question&quot; of what if a Speaker goes rogue), but the initial technical answer to you question is &quot;the Speaker of the House of Commons&quot;.