Also, I'm not sure if this constitute "illegal brokering" because currently I don't have RE license. 

What constitutes a can't lose deal?

The BP community can help you determine if it constitutes a good deal and worth doing a deeper dive based on initial rough analysis.

In your contract it should be very clear what constitutes "the closing" depending on the structure of the financing?

In most states, that constitutes grand theft, a felony.Apparently, he does this as a matter of practice.

(I need to check with my service to see if their inquiry constitutes a soft or hard credit check.)

They agreed that a contract is an interest in a property that could be sold and doesn't constitute a transaction that requires a licensee.

(from what i've seen it can be anywhere from about $10k to $20k per unit)And on a side note, rent control is shocking and do not understand how it does not violate the taking clause of the 5th amendment of the constitution.

Explain to the tenant what constitutes an emergency or urgent need vs what can wait.

Most more sophisticated contracts and commercial contracts say that selling your interest constitutes an assignment, but most residential contracts don't mention it at all, so there's nothing stopping you from doing it that way.