Selectable PC Personalities

Well, let's see. Let's take Minsc and Mazzy, since you mention them.

They would have to retain their names... if you didn't have the names, VO would be impossible (or they could just never refer to their own name ever). You would also have to keep their general background, like where they're from, or any talk about their past is impossible. Now, for Minsc, you need to take out any banter or dialogue that refers to him being a ranger. Unless you enforce him being of good alignment as part of his "personality type", you also must reject any lines that refer to him fighting for good (which is a lot). Mazzy must also have anything referring to her being a paladin, following the paladin code or being a halfling removed. So what are you left with? Essentially the small set of banter lines used in BG1, though I suspect many of those would also need to be replaced with more generic lines where the character did not discuss their profession or race, as well. Did that work? To a degree. There are many people who found the BG1 NPC's have lots of character despite there not being a lot of dialogue for them. It did not, however, approach the depth that the BG2 NPC's received. But you could NOT take the style of a BG2 NPC's dialogues and just apply that to any PC you rolled up and gave a different race and class. The more things you decide can be "variable" in this PC personality set, the more generic it has to be. Trust me: there is a big gap here between the theory and the practice.