How low of a credit score should I accept?

Also he would want to know if you ever owned or bought investment properties, or just heard on a crazy website or from a guru tht you need to make a bunch of ridicules low ball offers.

Any recommendations for banks with low fees/complicated setups (setting up a Wells business bank account was basically hell) etc?

He wants his security deposit back so he can pay it to the next landlord to get a place to move, if it's low income, you gotta realize most don't have savings and he wasn't planning on moving when you bought it.     

If you focus solely on the rate you may give up great future deals trying to hold on to your currently low rates. 

Vacancy rates might be one of the major downsides here, in addition to low population/job growth.

I am looking to keep my loan costs as low as possible.  

Maybe get a low priced master lease afterwards allowing you to make good profit from subletting.

If you are using 3%+ rent growth and assuming low vacancy, then I would wait.

You'd find that in a private money loan and there are low interest-rate loans right now, even on the private money side, at least in CA.