Talk to a CPA.Also, you are correct that there could be liabilities out there that would all of a sudden become yours.

You're correct about the subject-to. 

if i remember correctly, 1031 has to be done within 6 months time frame (e.g. sales and purchase can only be 6 months apart). 

I expect a clean place, correctly represented, with the owner available by phone, or text should there be a problem.  

Also is your Down payment correctly calculated?

@Michael A PiersonIf I understand correctly, you are looking for:1.

It has many benefits, but it also helps a lot because you only have to work with a single EIN and can use a single bank account with the correct bookkeeping to operate all your investments, to prevent commingling of your finances.

I would bet you’ll be lucky to get 100 bucks a door realistically when all the corrections are made and it’s running .

I wouldn't think that it would cause an issue with the mortgage, as that didn't change from when they did their appraisal - it was always a storefront, correct?

During the process the town inspector will come out to make sure that framing, plumbing, electrical, etc. is done correctly.