Keep your payment at no more than 35% of your income and minimize your credit card and auto debt.  

It gives you the flexibility kind of like a credit card that allows you to borrow a certain limit and withdraw funds as needed.

. - I will ding their credit such that all credit cards and other debt will cost them more.- I will keep their security deposit for funds owed.- I will do my best to garnish future wages until their debt to me is paid in full.This has worked 100% time so far.  

0% Business credit cards + hard money loan = 0 money out of pocket.

Similar to a credit card.

With your experience and possible skillset, perhaps finding a company to sponsor you for a green card may be a better option? 

Should We:Sell, take advantage of the capital gains law, move, and pay the mortgage off on the new house, credit cards, etc…?

If you have a credit card with a high limit or a line of credit on the existing duplex that might give you some wiggle room.

I gave out about 2000 business cards in the first few years.

They look at your credit profile and get you business lines of credit and credit cards.