I like the theory behind splitting up the dual social stats. I could see how that would work - when you level up, you get one point in physical attributes, and 1 point in Social attributes, but you couldn't spend one of the attribute points in the other category.
I think that's a bit too much of a radical change at this point, though.
Besides, I actually like the more random aspect of the co-operative decision making. I like the idea that you cannot purposefully build your character to win every argument. A lot of games let you max out Charisma and Speech attributes to talk a miser into giving you all his money, but it's the element of unpredictability inherent in the Original Sin's co-operative decision making that's really unique.
Nothing is stopping you from pumping your warrior's intelligence or your mage's constitution or your thief's strength.
One of the things Larian wanted to do with the co-operative dialogues is to emulate the feel of tabletop RPG's by giving every player a voice. This system emulates them in another by letting your fate rest on a fickle roll of the dice, knowing that a bad roll and your carefully thought-out plan can be shot straight to hell, and then anything, anything at all can happen next...
