Actually what about overwriting spacebar for the compressed air jet? We're not going to need minute jumping when we have this high-velocity monster working with us. Also, along with this, having a little guide saying what key does what in bottom print would be nice, togglable with Light Key so that you don't have to look at a tutorial every time you fly around with it.
Also, if I may put in my two cents for right vs left click preference, left seems naturally stronger for slashing since (at least to me) it is a stronger finger than right, and right seems like a more auxiliary usage key.