Hi!
I haven't try E on the zaurus, but I have been using it on every unix box since... uhmm, I don't even remember. I just love its simplicity. Let me know when you get an ipk ready, please.
About your problem with the mouse, at least in my actual laptop configuration, the menus stay on once you press with the mouse in the background, without having to keep the mouse pressed, shouldn't it be the same behaviour on the zaurus?
Best,
Luisico