Heh heh. Don't worry about it, it's only a game
Charisma is just how much influence you can have over other people. The child of Bhaal will probably have a very high charisma as they have the Godly aura of superiority about them. Plus, the intelligent son/daughter of murder probably wouldn't go around telling people who their father was anyway (can you say "witch-hunt"?).
JR Jansen: Wisdom and Intelligence also help budding young fighters out in that high levels of one or the other or both greatly aids your resistence to charm, hold and confusion-type spells. Minsc really annoys me sometimes in that his low wis and int make him very easy to charm or confuse (thus i give him a helm of charm protection, but he still gets stunned or confused easily).
And it's true, high charisma actually gets you different (ie:better) rewards on some quests. I can't think of any situation where low charisma is a good thing. But I play as a Paladin so I HAVE to have at least 17 charisma anyway.
When you are creating a character, make sure you get a decent roll, it might take a while, but then you'll be able to have plenty of high values in many attributes. On a completely legit (and VERY lucky) roll my Paladin got enough attribute points to deck himself out with 18/81 str, 18 dex, 18 cons, 11 int, 15 wis and 17 char. Now THAT's a solid character.