Can you burn your own house down? If someone had a house with nothing flammable near it, and they wanted to burn it down (no one is inside or near it, and no fraud is involved, and nothing that releases harmful chemicals when burned is in the house), is that legal? If not, is it arson or something else?
Check with the local fire station. You will probably be required to get a permit for a large fire, but firefighters are sometime interested in participating in burns of condemned buildings because they can get training from it.
Doing nothing is legally safer than doing something, but you're not without hope if you pull the lever. Although you'll likely have committed murder or at least manslaughter, case law is littered with lenience in exigent circumstances, even where convictions have been affirmed. Because this is a philosophical problem, there are plenty of opinions from that perspective, but not so many from a legal standpoint. Let's assume that you're an innocent bystander, (not an employee of the railway company or the train company, etc) and have no duty to act. If you do nothing, then it is unlikely that you would be charged with a crime - you had no duty to fulfill, and therefore not negligent. There's little doubt that not pulling the lever is the safer option. More interesting is when you choose to pull the lever - then it's probable that you would have charges of murder, or at least manslaughter, brought against you by the state. What defenses does the law offer? Let's assume that you are aware that pulling the lever will kill a person. The primary defence is a legal principle of necessity: where your criminal actions are not protected or excluded by some other statute or principle, the fact that you were obliged to take this action in order to prevent some greater harm may safeguard you from penalties. There are certain elements of necessity: That you did not create the danger that caused you to commit the crime; That you ceased the criminal activity as soon as practicably possible; That you had no reasonable alternative; and The harm that you prevented was greater than the harm that you caused. I see such a defense only possibly falling over on (4), where the prevented and caused harm, in the case of human lives, are inherently very subjective. Unfortunately, each state has different rulings regarding the threshold for evidence of this defense. One of the most famous cases where necessity was attempted as a defense to murder, with remarkable parallels to this hypothetical, is that of R v Dudley and Stephens: A crew of four found themselves on a lifeboat at sea with no food and no water, and with no prospect of rescue. One of them was a child (Parker) and was nearing death and unconscious. Two of them (Dudley and Stephens), after some discussion over drawing lots, decided that the child would be killed before his natural death, in order that his blood be better preserved for drinking. The last crew member, Brooks, was silent on the matter. After killing Parker, Dudley, Stephens and Brooks fed on Parker's body. During the trial, the matter of necessity as a defense to murder was considered. The judges found that there was no common law defence of necessity to murder, and Dudley and Stephens were sentenced to death with a recommendation for mercy. The Home Secretary commuted their sentences to six months' imprisonment. This case concerns essentially the choice you're making in the trolley problem: either the four crew members were going to die, or one of them would definitely die and the others might live. It's easy to say that they should have just waited, but they didn't have the benefit of hindsight. It's also a great example of a situation where although the law says one thing, it doesn't align with our morals and ethics, and while it's a UK case, I would wager that almost every lawyer in common law countries would have heard about it.
Yes, of course. Anyone can walk up to a shop owner and ask them pretty much whatever questions they want; police have just as much of a right to do that as anyone else. The shop owner doesn't have to answer, but police are free to ask.
If you buy a house, you can generally rent out a room in the house, unless in that jurisdiction there is some law against renting rooms in houses (that's actually a condition in my neighborhood, one widely ignored). If it's legal to rent (lease) a room, it is generally legal to sub-lease that room – as long as that's allowed under the original lease contract. I have never heard of a jurisdiction that has a blanket prohibition against subleases. So as far as the actual question goes, the answer is, "yes". The links are about something a different, namely rent control law in San Francisco, and the question of whether a tenant can be evicted from a rent-controlled unit because the owner wants to move in to the unit. Owner move-in eviction requires a specific procedure for giving notice, and the links are about these requirements. Conceivably, though, the question could be whether a person can buy a house that is being rented out, do a proper owner move-in eviction, and then lease a spare room. The SF rent laws require a good faith intent to move in and use as the primary residence for 3 years, and nothing prohibit subsequently leasing a room. Those laws pertain to evictions, not re-rentals. (It should be noted that once eviction under section 37.9(a)(8) has been carried out on a unit in a building, no other unit in the building can ever be so recovered. That could mean that the room in the house could never again be recovered, if it is considered to be a separate "unit" from the "unit" that is the whole house).
In many countries (for instance, the US), churches and mosques are private property. In general, the owner of private property can throw anyone off their property; claiming you're doing an extensive period of praying doesn't matter, because they are under no obligation to let people stay as long as needed to pray (they can kick someone off the property for just about any reason). If there's a contract in play things are different, but contracts aren't in play in this situation. That said, nothing stops the church or mosque from letting the homeless stay there; this is actually not that uncommon (charity being a fairly common religious virtue).
In the United States, the government has, multiple times, destroyed homes while trying to catch a fugitive. And the homeowner sometimes makes a claim in federal court that this is an unconstitutional taking without compensation in violation of the 5th Amendment. In Lech v. Jackson, the 10th Circuit decided that the police and city were not liable for destroying a house while trying to arrest a criminal who had fled there. The Supreme Court declined to hear the case. But in Baker v. City of McKinney, Texas, less than 3 months ago, a district court declined to dismiss a case in which police destroyed a home to catch a fleeing criminal. Allegedly, in this case the police were given a key to the door, a garage door opener, and the code to the back gate by the homeowner - and instead of using those, they used explosives on the garage door and used a BearCat to knock down the fence and the front door. I'm not sure to what extent those facts, perhaps showing that the scale of the destruction was unnecessary, matter. To the best of my knowledge the case is still ongoing.
One of the biggest problems here is in proof of injury attributable to an individual... With asbestos, you can prove that direct exposure in a certain instance caused a long-term harm. Just because you were around asbestos doesn't mean you get lung cancer, so if you don't actually suffer any harm (or any harm yet), you won't get awarded damages. Similarly with lead, you have to prove both the exposure, the entity which exposed you to it, and harm that you suffered. Just being around a lead pipe or paint doesn't mean you get damages, you need to have suffered harm. The problem with second-hand smoke is that you can be exposed to it from many different sources. Any problems you have (lung cancer) would need to be proven as a direct consequence of one specific (or prolonged) exposure. I could see this working if a non-smoking spouse developed cancer from a smoking spouse being exposed to it for years, but you can't just say "I walked by Joe Camel in the street while he was smoking now I have cancer and it is his fault". So the issue becomes who is responsible for your damages. You can't narrow it down to one smoker (or even cigarette smoke, as lung cancer can develop from other sources), so just proving that your cause-effect is directly related to smoke will be difficult. After that you can't say one single person caused it (unless they forcefully locked you in a room and chain-smoked for a year). So who do you sue? All of smoking society? You might just as well sue God for putting those people on earth, really the only recourse you would have is to sue the tobacco companies, the individual smokers are not going to be held liable as a group.
The customers are able to leave, so there's no reason it could be a crime. Even if they weren't able to operate the lock themselves, they are presumably able to leave by asking a staff member. There is no way this could be remotely considered false imprisonment. Depending on the layout and size of the store and presence/lack of other fire exits, this might violate fire safety regulations.