I think paying off a loan with a high interest rate debt and adding to the principal is one way to stay liquid within the property. 

Typically those are shorter stays as they are doing something for a couple months vs staying for the entire semester or year.

And stay with it. 

I am based in Texas and I understand that there is a lot of affordable duplexes in Westmoreland County for a low as $90,000 on Zillow.If you are looking to House Hack like @Madison Stoner  I recommend you interview some local Investor Minded Real Estate Agent and hire the one you feel most comfortable with.

In 30 years, I have had one eviction (in NY) and the court would not grant it and they ended up paying and staying for two more years.I think the multiple owners is more of the problem than panicking in advance about tenants.

Just ensure that the projected rental income comfortably covers the new payments, including the HELOC.

Stay at it.

Since I have damage protection waiver in place I feel more comfortable asking for a smaller deposit.

Will you stay local and on base or have the potential to be deployed?

The biggest challenge for being a great realtor is always generating leads and staying organized.