Compare that and the refinish price against another surface and see what it more cost effective/looks better for what you are trying to do. 

This just scratches the surface for you. 

I've found that an oil based strong smelling cleaner with pine or citrus gets rid of the smell of smoke on hard surfaces.

That all being said, this SOUNDS on the surface like an opportunity of a lifetime.   

I lost about $3k when a toilet backed up due to a connected sewer line in the adjoining house.

Be sure your repipe is correctly done, typically in MF you have back-to-back kitchens and/or baths, with a single branch line feeding one or more fixtures in adjoining units, especially bathtubs.

As an FYI, the roads in the Shores are all named after trees and then the adjoining roads are variations with the same tree name - so you will have Locust Road, Locust Loop, Locust Loop Run, Locust Circle, etc, etc. 

I've seen lots of little spots where somehow the surface was damaged.

There are quite a few multi-family properties that are very low priced that I would like to get started with, and the numbers look good to me on the surface (other than these ridiculous property taxes)... but can anyone add insight on expected vacancy percentages, expected annual rent increases, or issues with city inspections, etc?

Are hard surfaced roads needed;  Concrete or asphalt-  Cost of entrances must be offset by units.