Do I lose Crusader if I pick the eight dragons?

You mean to dismiss all but 8 cast memebers at the end? I'd keep Terra, Celes, Strago, Relm, Locke, Mog, Gau, and Shadow. I suppose you have to get Celes, Edgar, and Setzer to not fail Kefka's Tower.

Otherwise there could be plenty of topics about character variations.