1) intensify or heighten work
2) I think "unacceptable" or "intolerable" would work better.
3) "returned" in this context: to give back to the owner. If instead you meant to make it like its original conditions, then you would use the two words you have and change the owner part to refer to condition.
4) it works
5) works
6)works, but the word is not commonly used in conversation. More for writing. But it does work and is correct.
7) "appealed to" but "petitioned" would work also