I think that some dialogue options will only occur, if your WIS is at least 13 (a chest in Sahuagin City, a "Dragon Slayer" in Trademeet). Well, for a hardcore killer fighter this is probably useless but I prefer a PC who doesn't need potions of genius (lots of) or insight to spell his name or to remember his mission.
I like Boo but one rodent is enough...

Hmm? Maybe I should go for a fighter with solid all-round figures but lower the carisma.

I hate the tought that my char runs around as a complete idiot. I normlly give him Int 13 or 14 for RP-Reasons, as I don´t like Chars with low or avarage Int in PnP-RPgs, too. OK, sometimes (as in my current game) I make have only Int 12 for my Paladin, but 12 is absolute minimum for me.