(So you don't help to build up the rest of our medical bills through the medical system of course.)

There is often a time limit on how long you are exempt from paying local taxes on foreign income, and of course you will owe the US for life. 

I wonder if the tax forms would be mailed there, and then that trust company will file to IRS to explain it is tax exempt? 

Just because it's a primary residence for him doesn't automatically exempt your portion from capital gains—you're still considered an investor.You also need to think about what happens if your friend can’t buy you out or if your relationship changes.

If you got of law school, medical school, dental school, or grad school, you could still qualify. 

It does well as it attracts medical, academic, athletic, and entertainment.

Fair Housing may not apply to this landlord: https://www.equalhousing.org/fair-housing-topics/exemptions-...2.

Holding Costs, what are taxes, are there agriculture exemptions.5.

Since this was your primary residence 2 of the last 5 years you would be exempt from taxes on a sale up to $250k in profit ($500k if married filing jointly).

.- Watch out for residential tax exemptions, and be aware of which towns / cities have them.