I just don't see the Charisma Mod as being unimportant - it determines how often you can do it in a day. Now, currently the rules are that you get 3 + Cha modifier per day - which means people never run out. In fact, the only reason people take Extra Turning is to get 4 extra greater turnings or to qualify for feats and prestige classes.
But if you could only do it
once or even
never without a Charisma mod - you'd see people caring about their Charisma modifier a lot more. he current problem is that since all Clerics have more turning attempts than they need - the bonus turning attempts aren't worth anything. If the default was
less turning attempts than you need - it would suddenly matter a lot more.
I don't think we should encourage or require massive stat inflation. Jozan has a Charisma of what, 19 at level 20?
What if instead of turning and destroying undead, the turn check caused status affects. For instance, what if a normal turn success caused the undead to become shaken (even though they are immune to shaken iirc). A turn success where the undead would have been destroyed causes them to flee.
People wouldn't even bother to use Turn Undead under those circumstances. Undead don't have that many hit points, and every time a 3rd level Cleric is Turning he could be casting Knife Spray.
However, I would like to see more graduation in effect. Perhaps DC 15 + Level and:
Fail save: Shaken
Fail by more than 5: Shaken, Turned.
Fail by more than 10: Shaken, Turned, Staggered.
Fail by more than 15: Destroyed.
And Evil Clerics could have something similar:
Fail save: Shaken
Fail by more than 5: Shaken, Rebuked.
Fail by more than 10: Charmed.
Fail by more than 15: Commanded.
Or something along those lines. Make turning a bit more exciting. It does has the problem of being more like Blasphemy and Holy Word, however.
-Frank