I don't care much for BZ2's normal control setup, so I've taken the liberty of changing it around to one that seems much smoother. It helps a lot, particularly when it comes to running and changing weapons -- and is as follows.
First reassign you controls as follows
Prev. Weapon: Wheelup
Next Weapon: Wheeldown (remember to click on 'clear' first, because you are going to use mouse2 for multi-select)
Jump: Left Shift
Weapon Linking:
Multi-Select: Mouse2 (Right mouse button) (clear the old bind for this, since shift is now bound to 'jump')
Multi-Select Toggle Weapon: Mouse1 (Left mouse button)
To go into weapon linking setup, all you have to do is hold the right mouse button, scroll to the weapon you want to link to, and then leftclick.
Also, if you're fast running, using the shift key to control your jump thrusters is better because it allows you to go forward+right+jump at the same time.
Well, to each his own, I guess.
I have one of those ZMerc ZBoards (gaming keyboard):
Mouse1: Fire
Mouse2: Jump
Middle Mouse: Use Special
Mouse Scroll: Weapon Switch
WASD: Movement
Space: Select
Leftshift: Change radar mode
V: Target
F: Hop out
C: Deploy
Etc.
I use the defaults and change the mouse a little...
Mouse 1 = fire
Mouse 2 = special
Mouse 3 = (damn, can't remember)
Mousewheel = change weapon