On top of that, what's considered less lechatchila? Is non glatt less lechatchila?
I know people of Italian ancestry (lav davka Rome) that know for certain that it was ruled totally mutar for them to drink סתם יינם.
No I would call glatt a chumra that was generally accepted by the ashkenasim.
There are certain shailos where you can use certain kuelos and or multiple kuelos depending on the circumstances. Nothing specific off hand.
Stam yayin is a hard sugya to be Mattir because at the end of the day the gemaras and poskim due paskin it's assur however improbable.