You are flying blind and trying to use a calculator as your guide.

They were robbing me blind...all except for John.

Replace the blinds, get rid of the carpet, change out the light fixtures, and do a fresh coat of paint.

Any related advice or blind spot ?

And they broke all the blinds and want their security deposit back since it is so clean and landlord don't need to clean it! 

Then you simply deny them.What it does, unfortunately, is induce people who aren't qualified to apply because you can't exclude them in the advertising or on a blind inquiry.

@Chris JohnThat sounds wonderful. 37 doors, part-owner in another business, and not all your time is spent on making sure your property managers don't steal you blind.

Quit being blinded by meager cash flow.

For example, if I accept a VRBO booking, it's like going in blind. 

@Jeremy Staggers Houston has plenty :) American Title Company of Houston/Patriot Title/Capital Title ... all of them have 10+ branches  and they do all sorts of things for investors (e.g. expedite title search, loan doc prep, double close, blind HUD etc) ..PM me if when you have a contract and would be more then happy to introduce you to one of them.