One-person rental units are in the highest demand, and co-living directly appeals to this market.

I personally have success in doing flips with my partner here in Ohio.Lakewood and Edgewater are gentrifying neighborhoods in Cleveland.

One person's crazy is another person's sanity!

My personal preference for a buy and hold would be an already established area (or an area that's still gentrifying, but has already seen significant progress). 

@Matt Solis would be the perfect person to speak to about this!

My recommendation would be to engage an investment property focused realtor (not a general residential realtor) and let that person guide you through the process from pre-qualification to market/property valuation and selection. 

Personally, if I were to sell the stock, I would buy more property, not pay off the existing one. 

The vast majority of contractors won't want to give bids on properties while under contract unless they have a relationship with that person from prior jobs.

The question is, what is the intention  of the owner, not what would a reasonable person think is the intention of the owner.

@Jae Jun: Although the conversation has changed much, and toned down regarding proposed restrictions, the plan from jump has been to allow anyone with an existing STR, so far defined as a place that's been rented STR at least 2 consecutive days in the last 6 months, to get a permit and be grandfathered.