-Your FHA inspector is going to have to walk into all available spaces in the property and your loan will not be approved if there is an additional living space (non conforming unit) on the property. 

Go for a single or even a walk...What do I mean by that?

You gave away control of the situation and you're going to get walked on until you take it back.

walk down memory lane.. 

In many cases, the floor between the two is a conventional wood floor- i.e. wood joists, subfloor, and floor with carpet or tile as a walking surface.

This village always requires a walk thru by the building dept  (so no doing stuff without a permit) and man was the write up of repairs long.

:)now, here's something... when we bought our house 13 yrs ago i knew nothing about remodeling. so when taking the wall paper off on one wall, 4 layers of wallpaper came off and some of the plaster. had no idea how to patch it, so we bought a bhear texture paint in a can that you apply with a special roller. and then we painted on top, so the bumps are smooth.so now, we have one accent wall in the house that's texture and everyone that walks in thinks it looks like art because we added some shapes that do not have the texture. even plasterers have commented on stealing that technique.. :)

Have leases available and a list of questions to discuss during your interviews, and give tenants whatever required advance notice is necessary for inspections during the scheduled interviews so potential managers can walk through the units with you. 

I think a decent litmus test is that if you don't feel 100% comfortable walking in the neighborhood at night, you should avoid investing there.

A GC will be able to provide an accurate price but especially if you are new to using them may want to be compensated for the walk through.