If you have a signed agreement by all parties take it to a local lawyer for review and advice. If not, I don't see an actual agreement here.

First you need proof of things you are alleging not just alleging them. You filed with the EEOC they will either proceed or issue a right to sue...

Is there a provision in the contact that says what will happen if permits are not issued? That would be the place to start.

Check with a lawyer in your state, sound more complicated than a simple answer in here without seeing all the documents.

I agree with the previous answer. You could have liability if he is not licensed or if the county or city requires permits.

Tips are considered pay. One issue would be why did you except the bills--how good a fake was it. Check with a lawyer in your state.

Read the terms of your written agreement that will control everything. Don't worry about what the shed guy said.

You should take what you have to an attorney in your state so that your rights and options are fully discussed with you.

Is it legal? Yes. Is it enforceable? That depends on its terms of the agreement. Negotiate ones favorable to you and get a lawyer involved.

You are not asking a legal quesion but rather seeking an attorney--this forum isn't for that. You can search for attorneys in your state in this...