Cast time is reduced by dex, which is why it's important for GC saders to have some of it. Paring down the cast time will ultimately reduce the time you stand there getting beat up. As for vit, you just need enough HP to survive the cast with things beating on you, plus a little bit fo wiggle room. A good number for GH is 9-10k HP. Of course, as your level goes up, you need less vit to get that high, so it's up to you.
Kroggles ensures the living stay living, and the dead stay dead.
Clobberella beats you up.
Teela Brown has a birdie!
Flosshilde communes with the very souls of the damned.
Walsung is actually pretty cool. For a guy made of metal.