Sucks, but have to dig in and minimize the fallout and then circle back to worry about the financial end of things. 

A good investment team will minimize your risk and save you time and money.

Overall I think you're probably right at that refi point with minimal if any HELOC/Cash-out.

Use Private Money or Hard Money Loans to minimize what cash you have to bring to the table (if any, if you use PML). 

In addition to that, syndication allows you to create a well-diversified portfolio that maximizes your profits while minimizing your risks.

I know that some people do it, but what a colossal waste of time and energy. 

If your doors have deadbolts and knobs, buy passage knobs (no keys) that don't, save a few dollars and minimize lockouts.

You should have a minimal increase regardless because that helps sustain the expectations of increases.  

I have listed properties on Airbnb before and have found that people generally take care of the place and maintenance expenses are usually minimal as most people just want a place to shower and sleep when they are in town.My question is, what should I be wary of with this type of arrangement?

This is not the master bedroom and is not even attached to a bathroom so I don't know what the intent behind the sink was when it was installed--seems like a waste of money to have a plumber run lines IMO.