Many sellers will not accept this since they are in second position, and it is very risky since if you default (higher probability for investors with no money and/or no skin in the game), they will most likely be wiped out during a foreclosure.

Lastly, if he ends up failing to pay rent and is one month behind on rent, do I make him pay both months together as one payment or accept 2 different payments (one for each month)?

It is pushed over and over and over, especially on social channels and from service providers, and often interchanged with other terms and defined differently constantly, but mentioned again and again. 

You also kind of have to accept that you'll get nickeled and dimed every once in a while by a PM.

@Spencer ManningYour other questions were answered except for last one.S8 vouchers are for a specific number of bedrooms and rent amounts.So, a S8 tenant must find a property with rent that does not exceed their voucher amount.This stops S8 tenants from renting Class A properties and most Class B.Currently, Fair Housing does NOT protect source of income, so unless a state or local government has passed a law stating otherwise, landlords do NOT have to accept S8 vouchers.

For this, I'd recommend being prepared with the terms you're willing to accept in such a situation and staying firm.

You’ll need to find a GC on board with the extra paperwork and a seller willing to accept a longer closing time.   

The title company would not accept cash.

Yet investors expect a PMC to do all this extra followup for free because they think the program is "gold".We've always accepted S8 tenants and have no plans to stop.It's a decent program if the investor understands the limitations and challenges.Otherwise, it's "fool's gold".

My background is in Social Work, with a Master's degree.