Matt--what actions/behaviors did you observe that caused your "spidey-sense" to tingle on this prospective tenant?

Would it make sense to form this into an ADU or leave it as is?

And you create a situation where you are totally dependent.For most people in the US OOS investing does not make sense, the economic delta is not large enough to justify the additnal cost and management burden. 

I agree it makes no sense to hold onto this condo once she passes.

Buying this house will only make sense if you're getting something of value in return as far as a business deal.

Hopefully, this gives you a general sense, but I'm happy to help answer any other specific questions. 

If you find someone that seems to know a lot of people needing your services, wouldn’t it make sense to focus more resources on them?

Unfortunately many landlords take the first group they find in these situations and come from the ideology that all college students are slobs so no sense offering anything nice. 

The trolls are obvious to anyone with a little sense.

If you opt for the live in flip like I mentioned above it will probably not make sense to do a refi for such a short period.Hope this helps you some.