1) "Pattern switching is immediate", i would hope another possibility too. Like selecting the last step (it's already possible) then press shift and << or >>to select a pattern, and the pattern will only change when passing on the last step. And the possibility to choose the pattern number with external program change or cc. I ask my self if it's possible via software modification or if this is a hardware limitation? Have somebody found a work around for this behavior?
2) Good news, it's possible, press and hold drum, then press and hold mute, then a pad corresponding to the drum track you want to mute, the pad corresponding to the muted track will light on.
3) This feature is used to put a tie value, between all the step you press. It replace the gate value by a tie. Drums track == no gate value, so in drum mode no tie value too. But in drum mode, it would be interesting to put different step with the same method. Finally, it would be cool to hold shift and press two steps to reverse the statue of the steps between them a step on=off,a step off=on.