Initially I didn't have a personal connection to the area and didn't know much about the city.

This means, on average, that this person is facing foreclosure or bankruptcy, and has no other reasonable options.

Personally I think this is where a lot of sale lease back programs fail the seller.

I’m the last person who should complain about grammar, but these are yellow flags, at best.

There's no clear-cut answer IMO, it's a personal decision.  

Sometimes you will have that next person/family lined up and ready to go, but sometimes it takes much longer and you need do renovations or at least some repairs.

I personally am interested in creating a long-term rental portfolio but I'd be interested in hearing any strategy, ie. house flipping, short term rentals etc.

I personally use Hostfully and their support team is great!

If you need more to do the rehab, perhaps instead of partnering, you could get your former boss to do a personal loan. 

I have sold some properties years ago on lease options where the tenant buyers actually exercise their right and purchased the property. ( I was in the deed.)The reason I am concerned to tie another person’s property up  with the lease option is that people can change their mind, as in the seller.