I think with armour beind some kind of sword resistance, there should be a 'missile resistance' provided by any piece of armour - depending on how good it is at that. Take out one of the rather useless resistances (when have you last been turned undead?
) for it. But I guess it would require a lot of editing and revising, and would complicate things quite a bit... at least remove the explosions.
It would also be nice to have accuracy and maybe even damage depend on how long you 'charge'. Rapid-fire will then result in the arrows being spread a little farther and their damage go down by, say, 1-2. Holding the button for a second will make sure they hit home and adds 2-3 to the base damage.