I have a 5 string and the low B is much closer to the pickups than the other 4 so it's much louder. I'm not sure if I should raise it or lower the other ones.
I don't have much experience with bass so I don't know how it should feel.
Pickup height, judge bass by bass
Action is always such that when I play it reasonably hard, the strings just and so smack against the frets, but there are no long rattles anywhere. That clack helps clarity and attack for both the bass and guitars in a mix and takes a distortion very well.