What are some precautions a Muslim ought to take if he is practicing law in a non-Muslim country?

1) Would working on contracts between two parties with conditions that follow the law of the land but not necessarily Islamic conditions be permissible?

A typical job in such a field may involve a sale of a good or service from one party to another. For example, one party may agree to sell a product to another provided that they only use the product in certain ways. Or for example, when a company hires an employee, the employee signs a contract for the kinds of work they are required to do in exchange for certain benefits and salary. in the first situation, I don’t know if Islam contradicts, since I don’t know if someone can put conditions on the use of a product after they’ve sold it. I think this issue comes up with copyrights and patents, since typically, when someone buys software or a product, they make an agreement with the seller not to reproduce the work. But in the other situations, I don’t know if Islam may not say anything in particular, like with a job contract, there are laws of the country which are required (such as a limited number of hours or mandatory vacation)

2) Would it be permissible to work on getting injured or harmed parties compensation for their hospital bills and loss of income from their workplace which harmed them? (The level of compensation and what harms are compensated are also determined by the law of the land)

3) Would it be permissible to work for the federal government, and to enact regulations such as environmental rules and prosecute and fine businesses that violate these non-Muslim laws?