Thick/thin ring is a good call- so far I’m convinced they do nothing less well than a standard single ring, and some things much better, and at no major price penalty. Can’t see anything wrong with that.
Clutch mechs too- ok, they are heavier and more expensive, and not everyone needs them, but it’s otherwise all good news.
Flex-stem? I had one when they came out and it was ace.
God no. Didn’t really do much when new, then when the elastomer perished- which happened more or less immediately- it stopped being faux-suspension and became a hinge between your bars and your bike. Also more than averagely painful to smash your balls into.