Well, as for insanely high stats.....
My bragging character is a Half-Elven Cleric/Mage. It took me about 20 mins. to roll this, but I finally got her stats of
STR- 6
DEX- 18
CON- 15
INT- 18
WIS- 18
CHA- 18
I gave the Tomes of STR and DEX to other folks, but gave the rest of them to her. Add in the Gauntlets of Ogre Power and the Helm of Glory, and at the end of BG1, she had the best legit stats I've ever seen:
STR- 1

00)
DEX- 18
CON- 16
INT- 19
WIS- 21
CHA- 20
Holy Schneikeys! AC of -6, by the way (-4 if she's casting Mage spells.)
But as for the NPCs, and other characters in the TSR world, I don't really know. I think BioWare deliberately made NPCs that didn't adhere to the same rules as your PC (such as Coran having a 3rd star in Bow, or Mazzy being able to Lay on Hands), so that each character would be more multidimensional and therefore more interesting.