This is the sort of thing a Magic 8-Ball is better at answering than the Bigger Pockets forums.

As far as I know, my property is not Section 8 certified, but he and I submitted an application to the Montgomery County Housing Authority just to get the ball rolling (even though I understand there is a very long waiting list).Any other ideas?

Wanted to keep the ball rolling in this hot neighborhood.

You might also need to do some tweaking to your TIC relationship to avoid a deemed partnership scenario.https://www.accruit.com/blog/1031-drop-and-swap-out-partnership-or-llcJust some ideas to get the ball rolling.   

So would anyone has some experience and tell me « ball park » key ratios not to break in order to get likely to be approved by lenders.

You could offer a Lease Option with some amount of money as the option fee and payments of whatever is realistic until he exercises the option.

Otherwise, this is just an exercise sir.

Instead of me working the J-O-B all the time, it goes out and works to bring home more of itself each month.  

When the Option in the Option Agreement is exercised, there is a Purchase Agreement that is signed by both parties...just like any other sale of a property.

Boy Scout camping .Bears raided our camp and they has a paint ball gun with marbles to shoot the bears .