Charisma/Persuade could use some tweaking. I propose a few things to make charisma more valued:

1. Variable quest reward system that varies the payout dependent on the quester's persuade/intimidate/whatever. I know some quests already have an option to get some potions or whatnot, but I'm talking here about the overall payout, not just the bonus.

2. Some quests could be modified to perhaps provide extras at the beginning of the quest, depending on the quester's stats or a roll. "Say, you strike me as a nice lad. Here's an extra potion to help you out". This has SOME potential for abuse, but it is not without precedent (hook horrors, anyone?)

3. Perhaps there are more NPCs with useful tidbits of information(rumors to new quests???) that are only available through successfully persuading or intimidating them into giving it up.

4. Occasional Spellguard/Watch NPCs could be snookered through bluff/persuade into something, I don't know, letting you somewhere you shouldn't be? Giving a quest? Letting you go? This might be scriptable, or it might not.

Just thinking aloud....

Occasionally, bosses could be scripted so you can talk to them and make deals too. Inn keepers could be talked into lower prices, ship captains may be willing to negotiate lower fares. Hans could be talked into paying more.

There are many places that Charisma could become more useful. It is a highly under-used stat (minus sorcerers and bards).

I'd be all for being able to smooth talk a guard NPC into letting me out of jail earlier.

Well try making Cha Bluff/Persuade checks with Sten.

Instead of having DMS DO EVERYTHING!

You don't have to make or react to a skill check or roll unless a DM instructs you! But if players want to, it's up to their own discretion.