Doorf said:
Are you 100% positive EL book says that you can't have more then 4 attacks with more then 20 BAB, or does it say that when you advance to level 21 as fighter you don't get any more BAB.
Unless I'm mistaken, it actually says BOTH (and that's all characters, not just fighters). The ELH is quite specific that you never get more than 4 iterative attacks (TWF being a minor exception, of course). PERIOD. Otherwise, the game would bog down beyond belief. If you're the DM, you can surely rule otherwise, but I really don't think you want that. However, it won't really break the game in this instance, and depending on your interpetation, it's not a big deal in this use. A 20th level cleric burning a 9th level spell to duplicate a 6th level spell who gets +10 BAB and other benefits for 2 minutes. Powerful, yes, but not really hideously unbalanced. Rather clever, really. Changing the range from personal, though...I'd judge that as a 5000 x.p. cost (i.e. no freebies for the fighter).
The bigger danger is the can of worms such a tactic would open if you give additional iterative attacks for higher BAB. There are other workarounds to raise it, and you'll see them soon enough.
As for worrying about balance for a 100th level character....well, if you can find enough creatures to slay to generate the experience to become 100th level, then I really don't think you need to worry about balance at that point, do you? I mean, at that point, you're facing multiple archdukes of hell and dieties in single combat, so I don't really think that balance is a prime factor by then.