ExploderWizard - I think you are splitting hairs pretty damn fine here.
You're saying that if the dialogue is pre-scripted, then it's collaborative story-telling, but, if it is not, then it's roleplaying. I don't think anyone plays that way though. Even the most hardcore narrativist does not pre-script dialogue or scene. Their decision tree might not be based on the same criteria as yours, but, that does not mean that their decisions are any less spontaneous or creative.
Are you trying to argue that you only roleplay if you make the absolute most optimal choice every single time? That you play out your character's best interests regardless of any other consideration?
If that's true, than any character which has a weakness is no longer role-playing by your definition. The reason I'm getting this is from this quote:
EW said:
I think the real defining difference is the motivation for the character. If a character takes action A because it furthers his/her personal goals then we have a roleplaying based decision driving the action in the game. If a character takes action A because the group decides that it makes for a better story than action B or C we have active collaborative storytelling driving the action of the game. Do you see the difference?
If a player chooses to make a character that drinks too much, is that still role-playing? What if he only decides to drink too much this session, maybe because he's celebrating. He's not choosing to further his goals - he's actively harming himself.
Never mind the rather large number of games out there which rely on players taking interesting, but challenging choices in order to gain later benefits - Spirit of the Century and Sufficiently Advanced both do this. You can succeed right now, but it will cost you later, or you can take some sort of penalty now to have a really great success later. Is that still role playing in your view?
Heck, I would argue that almost every module ever written features the players "playing out a pre-defined "scene"" If you look at the set up of just about every encounter in every module ever written, the events of the scene are pretty easy to assume. If the event states, "The orcs, upon seeing the PC's, attack" is the group still role-playing? After all, the scene was pre-scripted.