1) Can you adjust sample start / end ? I've seen a video on YT and the guy was navigating a Rack then a Cell and then Sampler's parameters. And there was a parameter "S.Start" which I believe was sample start.
you can adjust start/end points in simpler within a rack, but not in sampler. the params for sampler are attack, release, transpose, and volume but only volume actually works when the sampler is within a rack. definitely a bug.
2) Are the buttons clicky or rubbery ?
they're in between. they have a good click to them, but when pushing down they flex slightly.
overall the build quality is great, minus the led inconsistencies. integration has a long way to go yet. e.g. the browser is basically broken: you can't browse any user content unless you put it in folders using the core library's folder naming convention, and even then it will not see .wav/.aif files.