Wait, so the OP wants to shine bright lights at enemies throughout various points of the series? Because that's practically all Gandalf did, in the movies. He was basically a glorified flashlight.
Curiously, in the only video of a staff I've seen, that's pretty much what it was. A glorified flashlight.
From what I can tell, a staff works more or less like it did in Oblivion, only you can dual wield it. It wasn't really until halfway through the third movie Gandalf started dual wielding though, and the Witch King destroyed his staff 30 minutes later, most of which did not feature Gandalf.