I don't know any of these kinds of investors directly but it's a good thing we have laws in place that require a process that prevents lenders from steamrollering people out of their homes. 

What you want to find is an attorney who is filing for "NOTICE OF FORECLOSURE OF THE RIGHT TO REDEEM" each listing will have the law firm listed that filed the notice.

Main living area has 3 Beds/ 2 Bath. 1 Bed/1 Bath 650 SF Mother-in-Law suite above garage. 

I know that assignments are the game, but I need to look further into the gray area between selling the contract and being considered as a broker for the property in question under NYC law.

Check your local laws, but in many cases if you (owner) is the one doing the cleaning, you can't charge for your time. 

@William Thorn just happened to me 10 days ago, 3 days before I was ready to close on a piece of apartment land the neighbor filed a lis pendes and law suit claiming adverse possession rights.

State law may require you to keep damage deposits in a separate account.

My question is are there any loopholes that anyone has seen to get around laws such as this?

Rent Control is pretty much laws created by the local incumbent tenants to keep out the competition.

Is he required by law to claim the interest when filing his taxes?