It's so hard to say generally what problems might come up, but the first that comes to my mind is work history - do you have 6 months on the job and a 2 year work/school history? 

We use Quickbooks Online for our main accounting software.  

That's a real bait and switch scummy thing to do, but I guess I shouldn't be surprised these days. keep in mind this is not usually bait and switch it could be and they are not being scummy.they simply are at the whims of thier senior credit facilities wants and needs..

Check out the free content online of Bill Faeth. 

This used to be a non-issue for FHA buyers up until 10 years ago when HUD stop allowing buyers to use their appraisalsKeep in mind your agent is not dealing with HUD directly. 

But i guess in today's world where things are on line and investors are used to Internet communications this is much easier than those days.

Keep in mind that many of these cheap homes are selling for less than a third of their insurance replacement value, which really means that the land has negative value - let that sink in.Most buyers who can actually qualify for a mortgage will get a PA for $200-300k and desperately want to upgrade their life.

Keep in mind that rates does not fully translate everything.

Did you have something in mind here? 

Do you have a city/market in mind for these investments?