You're... Saying Pao is good for game balance and
doesn't have hundreds of possible effects?
Anyway, let me just pick the bible:
-Turning the waters of one of the biggest rivers in existence in blood.
-People coming back to life.
-Giant fire tornados.
-Self-ressurection three days later.
-Bleeding holy water while still alive.
-Raining fishes and frogs and fire and whatnot.
-Dividing a sea in half (and then make it close over the pursuing enemy).
I guess if you mixed insane CLs with enough preparation, you could pull those up with "normal" magic... But they're completely suposed to be single effects, not Moises or some other Saint actualy being a completely cheesed out dual-caster with a dozen actions per round.
Anyway, if you stick an exp cost, and make sure it cannot be bypassed, wish/miracle will have built-in limits. More than Polymorphy ANY Object at least, that's for sure.