Do I have a case of discrimination

It is not realistic for an attorney to answer without meeting with you and dscussing precisely why this happened again.

My company is withholding monthly union dues...

Run to the union office and fill out the application in person. Pay the first months dues yourself. Then consult with an employment lawyer.

Should I sign a paper giving up my right to sue?

Every situation is different. You need to meet with an employment lawyer to discuss all the facts.

Can my employer force me to take unpaid time off if I still have PTO to use by the end of the year that will not roll over?

It seems that you are saying your time will accrue at the end of December and you will immediately lose it. Does not seem correct.

Can my comments in a "closed door" casual meeting with my supervisor be used to terminate me if policy says tell your supervisor

You will need to contact an employment lawyer to discuss if you have grounds to sue.

If they fail to respond, the agency can find them in default and take steps to enforce the charges against them.

Can I, as a writer of fiction, use a real company and its employees, in my plot?

Not employment law. More a question for a copyright attorney.

No paycheck

If you have a contact person at the Dept of Ed, you should speak with him or her.

Should a general manager of a franchise restaurant be made to pay money back when a deposit is stolen?

It is against regulations of the NYS Dept of Labor to fire you because you refuse to pay the money. Try to document the conversation somehow and...

Can i file a harrasement of coworker without my employer involved?

Other than quitting and applying for unemployment benefits, I do not think there is any legal action you can take. Unfortunately there is no law...