Early AM on sight improvement projects, with very loud power tools, check.

I've continued to make minor improvements along the way.

House hacking you can do the improvements and write all expenses off.

You can write off your taxes and insurance plus any improvements you make. 

Maybe increase the perception of value with some light landscaping in flowerbeds.Ultimately you have to “win” in the eyes of an appraiser so whatever you can improve to accomplish that will help.

Refi will cost you $$$ and you may need the cash to continue improving the property or paying more taxes if the reappraisal increases your tax base Also you may need the extra cash if a tenant can't pay rent. 

The numbers would still cashflow with one of the three units being owner occupied (vacant), and was thinking of doing AirBnB for my unit while away at school to help improve the cash flow while I'm gone.

It makes a big improvement for not-a-lot of cashola.  

But you can’t just look at the top / elite salespeople and say “I can do that no problem” and bet your income on it.Those top percent really hustle, even have to pay for additional staff to help them, and generally pay for additional advertising and services (eg professional photos, etc)Good luck.

When you are buying a rental that needs updating, you want to make sure you don't over improve it.