and yes I now have a prescreening message for any tenant leads so they have a clear understanding of what i require and then ask them to do a prescreening phone call for an interview if they are really interested then they can fill ip the application form etc.  

As AirBNB and VRBO introduce policies that have the effect of limiting the STR owners profitability, the long eatables operating properties are going more and more to off app rentals most of which is based on word of mouth which requires years in the business.Better off finding a business opportunity where entry level has more chance for success

I’d start with checking on their compliance requirements.  

However, items like plumbing and electric would very likely require permits and should be done by a professional

It is not that you can't rebuild, the rule requires that you must bring the structure into conformance with the updated flood rules. 

Is she entitled to previous joint returns with her ex if that is required? 

If the water bill is $100 a month, increase the price by 20% (or whatever you decide is fair) to compensate you for the time required to split and bill and to cover additional use when tenants squander the utility.

It's a lease agreement until the requirement is fulfilled.

Ask questions, get to know the renters, and document the condition of each rental so you have a record from that point forward and can hold tenants responsible for damages.Your offer to purchase should include a requirement that the Seller provide all documentation and agree to sign an estoppel certificate (also called an estoppel form or agreement).

Especially with most units requiring 3 different paints/colors: walls, ceiling and base/trim/doors.