Biggest Problem -  Finding labor and if you find it much much higher labor costs !! 

My biggest worry with a Section 8 housemate is that the individuals reason for needing assistance would be something that would make them a challenging neighbor, and you are not allowed to ask if a prospective tenant has a mental illness. 

With crowd funding, each investor is small and therefore this reduces the over the should factor you might get with a larger investor or HML.On the downside to crowd funding, it is a lot of work to do it right. 

Any and all additional information you can provide on the downsides or note investing, and particularly note investing through PPR would be very helpful.  

The biggest variable, I believe is how we value the input capital into the real property, what I will spend to be able to sell.

biggest issues are -raising hoa fees-poorly run hoa-too many rental units in complex making it harder to sell with conventional financing.

The only downside to doing this on a flip would be the timeline.

I use land trusts, but they can be complicated and my biggest issues is educating the end buyer about the power of those trusts.  

If you are in an area where everyone has a 2 car garage and your rental has a carport that's a down side.

there's no downside to more knowledge & access to more information.