My property is located in San Antonio.

And where is the property located?

After that, I would like to locate some properties that need to be fixed up and rents raised.

Needs some TLC, but is a great deal for a BRRRR.Tried to FHA loan it, but couldn't get around the fact that because of it's location near downtown, it is zoned as mixed-use commercial.

The Area: The town is Palestine Texas pop. 25,000ish the house is located in an older part of town but not in any danger zone.

Also, your preference of location and condition may restrict your opportunities if you are too picky. 

I'm wondering how significant this is overall regarding resale, and whether I should adjust the MAO to be lower than 70% to accommodate the location--or expect a lower ROI at sale.

depends on location, in a city they should be within .5 mi, in a suburb 1 mile and rural  5 miles but unique properties can be stretched further, I have done thousands of BPO's for banks, the rules were 3 listed and 3 solds, within 20% speck and similar condition, and make appropriate adjustments for differences, there is more art than science to it.

It's a nice location and in good condition. 

It's in prime location right next to the local college.