I have rehabbed three residences and flipped them as house hacks, but never purchased a building like this one that as purely an investment, so would love help on strategy and specifics. 

If you're looking for pure cash flow then that strategy will be different. 

I'm not looking for a pure +Cash Flow property in a bad area.

pure rent number is $1300?

My advice is from a purely legal perspective to insulate you and your LLCs from potential liability.

But from pure wealth building perspective, I think the math is pretty simple.If you really can not find any other investments which can return much higher than 6~8%, WL may be not a bad choice.

@Matthew GentileMy strength is as the strength of ten because my heart is pure.

I agree just to move for purely cash flow reasons doesn't make sense in the short term. 

From a purely water reduction perspective, a low-flow, dual flush (0.8/1.28 gallon) or single flush 1.28 gallon toilet if you don't think your tenants can master the dual, will save you the most ... especially if you are removing old 5-gallon/flush toilets.

That's without any major rehab, just pure market rents in a livable condition.