Put an upper mana limitation on Spiteful: Reveal a spell that costs less than (6? 5? Something like that). That would also make spiteful decks be able to run more spells that cost more than the limit, since those spells won't be affected.
Dark pact should cost 3.
Call to arms should cost 5. Even pally can't run it, and for odd pally it only summons 1 cost minions. Seems good.
Rogue quest should be 7 copies. Fuck that shit right in the ass.
Baku paladin should make 2/2's. It's the flood aspect that's a bitch. Helps classes that don't have tons of aoe.
I don't think Gul'dan or Doomguard are bad when you can't enable lackey/cube shenanigans on turn 6. Nerfing dark pact so that those kinds of things happen on like turn 8 makes it way more palatable IMO. Downside is now you can't kill Dark Pacts with Skulking Geist. The trouble with that is, often Cubelock can do lackey/pact/skull crap before you even have enough mana to play Geist, and playing Geist on curve is TERRIBLE tempo. Maybe make Geist cost 5 and leave Dark Pact alone? Eh, probably better to nerf Dark Pact.