Heh, I didn't actually know any of that stuff offhand. It just took a few minutes worth of digging through the game files with Near Infinity. It's a very wonderful tool for investigating things like this, and the ingame console makes accomplishing (or testing) fixes a lot easier.

Viconia's "Shar!..." dialog is always first, but to get the correct join dialog afterwards, the untying variable (viconiafree) needs to be set, and those three guys (her captors) need to be dead. You have to kill them while the game is paused, though, or they'll either walk off the map immediately or initiate glitched dialog.

Anyways, I'm glad it worked, and her inter-party dialog should be fine now. It's possible that BGT messed up her romance checks due to being dead, so if you want want to romance her but don't get any of the romance dialogs, you can jump-start those through the console too. Just post back here (or look up the great romance guide by Extremist) if the romance doesn't start.