They didn't buy the place, carry the financial risks and issues of ownership, they have no skin in the game as an owner and simply not entitled to the owner's equity forced into a property by their contributions......which already has a value range. 

You would not have the skin in the game and that is risk lenders are not willing to take.

Plus it might just save some newbies skin when they are doing their first lease.

Simply put, the buyer SHOULD have some "skin in the game."

There is more than one way to skin a cat so even with bad credit and low savings it can still be done, admittedly it will be harder but not impossible.If you can figure out how you are going to get control of that property first then you can go out and find it and craft your plan to rehab it and flip it.

They want you to have skin in the game.

Most lenders want "skin in the game".

There are a tons of ways to skin the cat in RE. 

Add to that the type of tenant you have to manage and the type of maintenance that would be required (with a tenant who has no skin in the game and who has historically been unable to keep their housing, for whatever reason)--AND they'd be living literally in my back yard?  

If you have ZERO skin in the game and he is going to split the cashflow with you 50/50 for 5 years, then he is an idiot (or perhaps it is a family member willing to help you out?)