The first point cannot be done, as far as I understand, unless your snare is in an easy separate column where you can just cut that out of the track and put it in a new one.
Similar for the velocity randomisation. Easy to do if the snare is in a seperate column: select your variables under the last tab Vol/Pan/Effects and make sure your Content Mask is set only to ‘volume’ if you just want to edit the velocity.
Other people may be able to explain this better than me
no the snare is in one column along with all the other hits
so it doesnt sound like its possible. shame, as using piano roll editors on say DP5 or cubase, you can just double click your note which highlights all instances of that note, then you can cut and paste onto a separate track where you can effect just that note (the snare in the example above)
would be cool if something like this ever got implemented, as it would make separating your kit onto individual tracks really easy.
For now my best advice would be to be each separate instrument into separate tracks. Use send tracks for cluster effects (e.g. global drum compression etc). This will generally aide you in being more precise with your mixing.