Like Greg mentioned, I would be concerned with his/her responsiveness while I was living there. 

Banks do not sell notes to just anyone off the street.When you acquire the note, you are now a lender with a collateral interest, as Dion mentioned, get a deed in lieu of foreclosure, you could give cash for the keys.Over the years I've done this many times before the words "short sale" were ever adopted in real estate terminology.

Why haven't any of the BP podcasts mentioned this?

I only mention this because I noticed your mention of Furnished Finder, which is the only platform I list my MTR, and FF caters to 30+ day stays. 

The only way to get help with the down payment before closing would be through a HELOC, personal loan, or private lender, as others have mentioned.

I agree with @Michael Baum do guests mention in reviews?

It was mentioned above you could refinance into a conventional loan, however with the 5% down conventional primary residence loan on multifamily now chances are you won't refinance this FHA loan unless you plan on living there for an extended period of time and rates come down. 

As Account Closed mentioned, the first question is to decide if you want to invest actively or passively. 

If you have the depth for an inside mount, I'd go that route with curtains, as mentioned previously. 

While the Agent mention that the seller would prefer no assignment, to which I acknowledged.