Can anyone tell me how the ticks of the volume and panning envelopes work? In Modplug Tracker it was dependent on the speed, so if you had a speed of 3, there would be 3 ticks per row, and so 1 beat of 4 rows would be 12 ticks long (allowing you to create accurate envelopes that, say, faded in from 0 to 64 in 1 beat). How exactly does this work in Renoise?

this works exactly like in all other trackers : the timeline of the envelopes are ticks, so they also depend on the speed but not bpm in your case.