More specifically, are they more fun to play with than WoC? I've got 3k WoC and I'm tired of simply picking a good army list and moving forward. I like the Daemon models, but I've never played with/against them so I don't know how competitive they are.

Some general question:
How handicapping is the self destructing magic phase? My opponent isn't playing chaos, so that lightning storm is only affecting me.
What's a good size range for core? I'm thinking of taking bloodletters and plaguebearers. Is 20 survivable? 30? Especially if I'm zombie crumbling.
Is Epidemius the all-time MVP or what? Reminds me of Dr. Festus…
I'd like to take a Lord of Change because I think it looks sweet, but I've never tried the lore of Tzeentch. It seems Skaveny.
Are bloodcrushers worth taking? They definitely seem lighter than skullcrushers.
Are there any cheese builds I should avoid?

Thanks ya'll.