The mortgage would stay under the seller's name.The buyer could then rent out the unit, renovate, etc. to increase cash flow or make more money.But aside from a possible "due on clause" being called by the mortgage company, what's the benefit to the seller?

I suspect that is unlikely with the increased need for housing.  

You are already paying rent, so pay it to yourself to increase cash flow and accelerate savings for the next investment. 

@Jordan Meltzer unless you find a screaming deal - a Class A property won't cashflow for 3-5 years.Class B: 1-3 years.Class C: most investors don't properly understand the risks, so should stay away from them.So, you may need to deal with negative cashflow, but plan on appreciation increasing your wealth.

The margins are tight which increases risk.

I recommend you do this annually to adjust for utility increases and other variables.

The shorter the prepayment term has an impact on increasing the rate.4.

A few months go by and unbeknownst to me the escrow account had now drawn negative which triggers the lender to no longer apply what’s considered a “partial” payment to them, given that I’m now paying less that what’s due given the escrow increase required but not relayed to me even though I expected it at some point.Last month I’m on Zillow looking at the value of my properties.

Which increases paperwork & costs for little benefit - if any.4) You'll need an entity in the US.You need to discuss all this with a qualified tax professional or attorney.- For our clients, we provide consultations with a tax attorney that handles over 300 foreigners legal & tax needs.

Currently we are seeing STR owners posting for sale due to reduction in prices they can get per night and the vacancy rate increasing.