Part of the reason they can chunk out lots of new episodes is that there are lots of opportunities for stock footage, such as the establishing shot of the lunch room, playground, classroom, and bus stop, and of course the class full of kids staring vacantly at the front of the room, as if Mr. Garrison is in some other dimension. We might see them re-use other scenes in the future so they don't have to re-animate them.
They'll always miss stuff like that... BTW, since when was it swimsuit weather in South Park?
It's probably spelled Bebe, and she had plenty of speaking lines as far back as Weight Gain 4000. It almost looks like she and Wendy are the only two girls in class.