Two excellent questions.
Through most of my adult life I assumed that I would never collect any social security benefits at all.
At 74 I have been drawing it for 7 years, and living here I seldom spend even half of it each month.
On the other hand, if the government in America turns Orange this year I thinks all bets on continued SS payments are off. Same for Medicare and Democracy.
As far as being able to stay here long term it's a daily crap shoot.
The world being the same as we know it over the next 30 years? :
Not a snowball's chance in hell of that.