For a person who is starting a film production company in Chicago, Illinois, is it better to elect an LLC or an S-Corp?

There are a variety of risk mitigating and taxation concerns to consider in both the long and short-term when forming your business. Your best bet...

How can i file for taxes i worked off the books and got paid cash

Report income and expenses on Schedule C of the 1040.

Does buying and selling cars effect taxes?

This is capital gain that needs to be reported. However, what you would owe in taxes is based on more than what you provided.

If I inherit property jointly with other beneficiaries, must I pay income taxes on my share if they "buy me out?"

Tax implications are based on the margin between basis and sale price.

2012 tax refund being held due to 2007 missing 1099-B

Do you have the 1099? You need to find out what the capital gain/loss is and then report it as either long or short term.

Can I give away my commission to a customer without being taxed on it first?

This would most likely be an expense on Schedule C of your 1040.

Must I pay federal income or Calif. state taxes on an inheritance of property, or cash, worth $75,000?

Have you sold the property?

Previous employer claims they inadvertently overpaid me.

You could end up owing if you were overpaid, but I would get a detailed breakdown of how and when you were overpaid first.

Did the painter paint for 55 hours?

Did the painter paint for 55 hours?