1. Personally, I would like to see Sokka come up with some hair-brained scheme that goes horribly, horribly wrong. Maybe he and whoever he recruits (read: probably not Katara, because she's too sensible XD) get captured (or almost captured) by the Dai Li or something. Or!!! Maybe one of them gets hypnotized and everyone else has to figure out how to fix him/her?
2. I second the idea of a silly Sokka/Ty Lee interaction. And having tension between Sokka and like every other girl XD
3. It might also be interesting if Sokka (or someone else) got captured by the fire nation girls and used as leverage of some kind.
Honestly, I'm not really sure what to do with Azula other than exploring the city. Although I definitely second was Mippa said - it'd be really interesting to run into Iroh and/or Zuko again. Maybe Azula could even do something like find out where Zuko is and start sending him anonymous notes or something to mess with him? Idk.
Also, re: Mippa: I love your Mai. This is why you should pick up another one. Yes? XD We (or rather, I) want YOU for the ranks of two-character BSS players XDDD