1- The more I play on a guitar, the more used I get to it. Though there are guitars that annoy me too much, and I just won't bother playing on them.

2- Low action = you don't need to push the strings as hard, so you can play more comfortably/faster, yet you can get fretbuzz and less sustain.
High action = more tone, harder to play

So the key is finding your own preference somewhere in between.