How do you check the legality of a new business model? How do you check the legality of a new business model to make sure it will be legal, and you won't be running afoul of some law you have no idea of?
Hire a lawyer, who is licensed and trained in law and who is obligated to be honest with you and advocate for your interests, and get him/her to review your business plan. He/she will point out real or potential problems with your ideas and plans, show you legal gray areas of the law and advise you on what you can and can't do. Some lawyers offer a free initial consultation. As an example, you can browse and read specialties and qualifications for legal help in New Jersey: https://www.justia.com/lawyers/business-law/new-jersey There's no substitute for real legal advice; not consulting with an attorney before signing contracts or starting a business can put in in real legal jeopardy. Don't ask legal advice from randos on the Internet, as they are not trained or licensed, and it is illegal to act or work as a lawyer without being licensed. As ohwilleke points out, you may want or need to consult several different lawyers.
Law SE is not for direct legal advice. You're in the middle of a contract dispute that has turned acrimonious and need to find legal help. Google for free or low cost legal aid in your area. If this "point person" has mentioned a lawyer or made legal threats, you do need legal help.
This would be entirely dependant on the jurisdiction. The things that would need to be legal to make this transaction legal are: Is the sexual act legal? Is gambling legal? Ongoing consent by both parties To make this an enforceable contract, in addition you would need: Sexual acts to be valuable consideration, basically, is prostitution legal? The fundamentals of a binding contract: intention, legality of objects etc.
Dale has the right answer, but I'd like to elaborate on why it isn't lawful (as compared to why it would be unlawful). I know it doesn't work that way on line, but it's simpler to think of a credit card as a physical piece of plastic. The bank will have issued this to their customer. It will have a number and an expiry date. You have no way of knowing whether a replacement card has been issued. Even if one has, the customer has authorised you to charge a specific card - you do not have the customer's authorisation to charge a different card with a different expiry date. By guessing the expiry date, you would be making a representation to the bank that the customer has authorised you to charge that card (if it exists), when they have not.
It is certainly possible to incorporate companies with the same name in two different states. If neither company does business in the other person's state under that name, it isn't actionable for either company. If one company was already doing business under its name in a state where another company is formed under that name, it would usually be possible to force the new company to cease and desist from using that name, either with an action directed at the infringer and the Secretary of State (or other official charged with business incorporations in a state) of that state, or in an action directly against the infringer alone. Also, even if a trademark isn't formally registered, it can arise at common law simply through use of a name in a particular market in a particular place. This is harder to prove and the remedies for violating a common law trademark a more limited, but it is not entirely unenforceable.
The general rule is that you must comply with all laws. The first thing that means is that you are required to know what the law is, thus ignorance of the law is not a defense for not complying. There are some special circumstances regarding notice, so a law must have been published. Second, whatever the law requires you to do, you have to do it, regardless of any difficulty you might encounter (e.g. you have to pay your taxes even if you don't have enough money). Suppose that a law is so onerous that it is literally impossible to obey it: you still have to obey the law. You have to file a lawsuit against the government challenging the constitutionality of the law, to get the law overturned. Frequently, more requirements are imposed on businesses than on individuals, but there is no legal difference between impositions on individuals and impositions on businesses in terms of laws being difficult to comply with.
While German law indeed requires providing correct contact information it does not require the recipient to answer queries. It is there so that you can submit legal notifications. In your case I wouldn't be so sure that the information is not correct. However, even if the contact information is incorrect, there is not much you can do about it. This is reserved to the following groups by § 8 Abs. 3 UWG: every competitor; associations with legal personality which exist for the promotion of commercial or of independent professional interests, so far as a considerable number of entrepreneurs belong thereto, and which distribute goods or services of the same or similar type on the same market, provided such associations are actually in a position, particularly in terms of their personnel, material and financial resources, to pursue the tasks, under their memoranda of association, of promoting commercial or independent professional interests, and so far as the contravention affects the interests of their members; qualified entities that prove that they are entered on the list of qualified entities pursuant to section 4 of the Injunctions Act or on the list of the Commission of the European Communities pursuant to Article 4 of Directive 98/27/EC of the European Parliament and of the Council of 19 May 1998 on injunctions for the protection of consumer interests (OJ Number L 166 page 51); Chambers of Industry and Commerce or Craft Chambers. Unless you are a competitor you are out of luck. The hoster or other providers can't do anything and don't need to, as they are not required to check legality of their user's websites. It doesn't really matter where you are by the way for these laws.
You can make a derivative work if: the original is not under copyright, you are the copyright owner, you hold a licence from the copyright owner that says you can, or your usage is fair use or fair dealing as applicable. For your proposal, the image is copyright, you don’t own it, you don’t have a licence and what you propose is neither fair use nor fair dealing. You can’t do it and you can be sued if you do.