As to your question about the mortgage, you'll want to research something called a "due on transfer" clause to determine if that is an issue for you.These are all things you will want to discuss with your attorney and CPA.

I also would add that even with all of that you can have issues with a tenant.

Check out places very well before you buy, looking at costs, checking the place top to bottom, looking up who owned it before, comparing prices in the area, checking out tenants, and looking at the legal stuff.

Plumber mentioned there is a ejector/grinder pump in one of the units that handles all sewage from all 4 units.They replaced the ejector pump and in 2 weeks, same issue happened with the sewage leaking in the garage.

Rent has been steady, no memorable issues we couldn't solve and continue the arrangement. 

It is not an issue if you are adding more square feet for your personal preference, but I would not expect an ARV that is as high. 

I might have a resolution by 4/1, but if it goes any further, then I'll pursue legal action for sure.

Any tips on dealing with these issues.

Min loan size may also be an issue at 70% LTV.

We walked away from one that we really liked after it was found to have some serious foundation issues.