Controls

All of it is rebindable under Options → Controls → Command Block Staff Addon. Out of the box:

Key	Action
Z + scroll	Switch ability (1–6)
Left Alt	Switch the current ability's mode
{{ "`" }} + scroll	Tune the current ability
V	Open the current ability's menu
Tab	Build modifier — paint, cycle shapes, summon, easy stairs
Ctrl	Pick Block (eyedropper) in Placement
X	Un-electrify what you're aiming at
C	Choke whatever you've got in the beam (hold)
U	Undo the last command-ability action
G	Get on / off the staff

None of these do anything unless you're actually holding the command-block staff, so they won't interfere with normal play.

Mouse

Right-click is the main action, left-click the secondary or the quick-chooser. Pick Block + right-click is an eyedropper anywhere in Placement — it's a real binding, so if you've moved sneak onto Left Ctrl you can move the picker somewhere else rather than lose one of them.

The build modifier is its own key rather than Shift, so building doesn't crouch you. Shift is still used where crouching makes sense: revealing what you've electrified, whitelisting someone into your shield, forcing a command target.

When a mode has something extra available, you get a one-line hint at the top of the screen. Those hints name your keys, sneak included — rebind it and they follow. Anywhere these docs say Shift, they mean your sneak key, whatever that is.