something to keep in mind about the original wording of this feat are the terms used. bonus to hit and extra damage. unless specifacally addressed by you the DM this means that they dump a high level spell for a big bonus to hit and dump a lot of little spells for the extra damage. this works because while bonuses are non stackable extra damage does stack. if you are planning on lowering the requirements of the feat it is even more important to keep this in mind. remember that the feat is a free action. so an easy way of dealing with this is to simply say it becomes a swift action (useable once per turn).