Located in Ohio.Interested in: small multifamily (sub 5), small apt (sub 20 units), self storage. 

So my immediate plan was to try to rent this house as a medium-term, furnished rental (basically leaving all my stuff here, taking a few select things) and moving in with her for a few months to kill a few birds with one stone - MTR income, not having to pay for a storage unit for my stuff, saving up more money for a down payment, and caring for my mother.

We do Self Storage mainly, but the above fits your background better.  

I'm looking at a potential self-storage deal which I could use some assistance with.

I'm not sure how feasible that it is, but that is why I'm on here asking the experts.

Self storage and country subdivisions.  

Storage units, industrial, raw land, development (a form of value add), zoning changes (a form of value add), office, hotel/motel, NNN, etc.  

You can also offer to gradually increase the rent (if feasible) or give them time to adjust, which can ease tensions.Requesting to vacate is the trickiest part, especially with a tenant who might challenge you.

I currently live in Silicon Valley but house prices aren't feasible for me here.

Such as storage, RV park, Mobile Home Park, etc.