Haha. Yeah, Cryx are tricky li'l guys. That game was my first try with the Iron Chef Asphyxious and he is just an amazing bastard. He would kill dwarves, grab their souls for focus, then use his super-cheap "now I move 10" away through walls and terrain" spell. Enron couldn't really get him, but in the end it didn't matter because I couldn't stop him from getting away with the trezor. Anyway it was fun but we really need to rewrite the rules for the Treasure scenario to make it quicker.
Anyway. So yeah, warcasters are balls rad, but they're not really intended to be the guys out in the thick of things. I usually find that when I am fighting with my warcaster, I am about to lose. For the most part you want to keep them just close enough to make their spells useful and give focus to the warjacks. There are certain guys who might be exceptions. The Butcher seems like one and so does Vladimir.
I recommend cherry-picking scenarios from the Escalation campaign. Look them over and possibly adjust them for 500 pts (although most scenarios would probably be OK with 750). The first Khador-Cygnar scenario has Khador defending a guard tower, and if Cygnar doesn't capture it after 8 turns you start rolling for the arrival of Khador's reinforcements (and thus the end of the game). Maybe 6 turns would be more appropriate for a 500 pt game.
Anyway even though the campaign as it stands is sort of cumbersome and unrealistically long I think there's a lot of good stuff to be mined from it.