Most investors I see renting near the university require college students to rent the property for a full year or they run the property strictly as a short term rental.

It can't hurt, but it isn't strictly necessary. 

@Ed EmmonsInterested, and is this strictly for properties in CA only?

thorough tenant screenings and strict, consistent standards are a must.

I have completely separate accounts and credit cards strictly for my real estate business.

Aside from the fact that I don't believe anyone is working that many hours - I mean really working, not just being available to answer a question that comes up or similar - anyone working even remotely close to that is going to be neglecting their family, their physical and mental health, their diet, their driving, etc.

Or do hard money lenders strictly give 60-70% ARV? 

I will suggest having a strict late fee penalty in your lease agreement going forward.

Years ago I had strictly cash tenants that I rented to but I started changing that after dealing with some of the "stories  I would get from them.

I don't know how strict the codes or building allowances are in the City of Chicago.