“1. can be samples previewed while browsing?”
what I do is I have a 16 step sequence runing and put a trig on a step, set the trig to sample using plock (turn synth down 100% in most cases) then just scroll up and down through the kit list and you can hear a different sample on each loop through the 16 step sequence - if you know roughly where in the kit where your sample is it only takes a few seconds to find it and hear it being triggered.
I’ve noticed that while listening to the wrong sample getting triggered you hit on things you migh not have been planning to do so hearing vocal snippet 6 in your loop when you’d been aiming for vocal snippet 3 can set you off in a new direction!