For example, do you require a $200/per door cash flow and 10% cash on cash returns or are you looking at a 5 year ROI that includes appreciation and selling costs?

That exception is that the warranty deed and title insurance will include an exception for the loan being taken subject to.  

We live in a revters town.If I get these homes I am thinking I can do two things.One if course is to rent them out and from the rent save the taxes,insurance, cap ex, vacancies, and repairs included.

TENANTS FROM HELL #11Car Fire From Hell.Running one of the largest rental portfolios in the Cleveland, Ohio area I have managed 1,000's of properties & dealt with countless tenants. In short, I have seen it all. F...

Peace of mind and money.Like the poster said above, make it effortless for them to relocate to a different place including a financial incentive.That's the only way I would move from somewhere that I liked.

My first was a vacant office building that I bought, renovated, and filled with four tenants (including my accounting practice).

That price is not including if the sewer line is damaged, with that I don’t know how much it will cost until I get an estimate this coming week.Also, advice on wet joists, will they dry out and be ok?

If you decide to keep it you might need to work on your master lease items that includes all of your rules. 

Let’s say you can buy it for 90k (including closing costs) and a conservative ARV is 125k.

I'm assuming that is $200 after all expenses including mortgage?