Um, I just checked and I didn't see any aftercon panel in the guide.
And there are a bunch of dances at KCon! After the Slants concert on Saturday from 11pm-2am (1am for minors) is a dance. Then on Sunday the Masquerade Ball is from 10pm-12am, and there is also another dance right after that from 12pm-2am (1am for minors).
I'm also a noob to conventions but if you have any more questions, feel free to ask ^_^