He does indeed have Improved Alacrity ( no pause between spells ) in the cutscenes. He's the most powerfull elven mage ever to be around, as powerfull as they can get. It'd look a bit stupid to see him cast a spell, yell "die !" and then wait around for a while before casting again.
Newayz ... if you want to experience a small part of the power jonny really has, download the improved Irenicus and shudder at a Irenicus with permanent Improved Alacrity, the Robe of Vecna and unlimited spells. It's without his personalized spells though ( the lightning and double desintegrate. special effects and stuff ) .. if he had that too, he'd be a touch unbeatable I think
