I have student loans out and only have a co-op (internship) that rotates every other semester, so would a bank even be willing to loan to me?

Yes, it also strained by capital reserve but fortunately it's still substantial.  

If the current tenants qualify under your requirements, can you put them on leases and over the next few years, rotate them out while repairing their units?

They usually live in a very small world that rotates around themselves .

WSJ says in this recent article that "despite historically low mortgage rates and rising wages, the housing sector has been strained by a low inventory of affordable homes propelled by rising construction costs and lack of land." 

I re-order kwikset keys from Amazon to not keep the same keys in rotation.

Trying to do both will introduce unnecessary strain and distraction into your life.

Also how many towels, sheets, etc do you typically keep in your rotation?

If that triangle is rotating around, spinning around, then water is being used.I looked again at your post and it appears you already had the main valve shutoff. 

Eviction of only certain family members can strain a relationship and most people hate confrontation.