Filed for child support modification and shortly after I received signed/notarized adoption papers in my mailbox.

Your child can't make such a decision. Be the adult and make a decision that is in his or her best interests. Frankly if a parent wants out I would...

1 )Can I invest in Retail business (Liquor business) with my brother who is citizen. 2)Will there any issues on my Green card

Wendy nailed this question. No further response necessary.

Just out of curiosity, can a Parenting Agreement be considered a Contract under any circumstances? (Breach of Contract)

A contract is a contract. I'm writing the remainder of this response to fulfill the word count.

If i sign a contract by accident for a service for a relative's home which i don't live in, is the contract still valid and am I

If you signed an agreement it is presumed valid until you can prove how an accident would have been possible.

If the building you live in is up for sale, how often is the landlord (or his real estate agent) allowed to show the property...

Unless the lease stipulates otherwise as often as is necessary to lease or sell it.

HOW DO I FIND OUT IF MY DECEASED BROTHER HAD A WILL?

Unless a probate estate is filed you may never know in that there are few Will registries in the USA.

Is it ok to file TAX while out of status ?

I encourage filing whenever possible to avoid penalties.

Business question

I believe it's still legal to pay commissions in America.

It's always best to record your conduct in written form.

Will bankruptcy allow me to keep my license if not what should I do next?

The bankruptcy won't assist with your privilege to drive.