I've battled a couple of Cresselia in the Mini-tour, and overall it was unimpressive. It is certainly annoying, though, especially with T-Wave and its insane bulk (Absol's LO Night Slash didn't even 2HKO -_-). However, like Uxie it cannot hit hard right off the bat. With Pokemon like Escavalier, Aggron, OTR Cofagrigus and Spiritomb in the tier, I can't see Cresselia disrupting this metagame too much. It will certainly give Uxie some competition, but Uxie still has a niche in Stealth Rock and U-turn.
Venomoth's nice base 90 Speed makes it a challenge to deal with, imo. I think we can leave QD Passing to Smeargle for now :3
Hmm, I think banning Durant is a fair decision. It resists most of the common priority moves, and it's bulky enough to find an opportunity to set up that 1 turn of Hone Claws to destroy everything. BW2 tutor moves have also endowed Durant with Superpower, making it a lot more difficult to wall with the likes of Steelix. There are handful of faster mons and Scarfers that can easily revenge-kill or force it out, though, so I can see it being a manageable top threat.