I have STRs in a college town, and I want to be renting to alumni, parents, business travelers, academics, and people in town for medical procedures at the hospital. 

I am 21 years old that has went to college fell out of college (due to a car accident that left me without knowing who I was), went to the air force and medically released due to "health problems", to making it halfway through to becoming a fireman.

Can I generate enough cash flow to pay for grad school in full every quarter/semester (medical school or business school) if I house hack?

Apartment building slower paying tenants more often.

Unfortunately, during that 5 years, my dad had some medical situations arise that have pretty much destroyed his credit.

That is what the SNAP and Medicaid/MediCal is.

It's near a local medical community college that I used to go to.

What are your thoughts on amount of liability or medical coverage?

I had them tell me what was going on and what they wanted to do with their life and the house they were already way behind because of medical stuff. 

If not I'd say take it a little slower.