IMHO, more than one CE is a waste of money (sorry). The CE to me is totally worth it for the physical stuff. The pets and SC2 avatars are a nice bonus, but really that's all that's added over a normal box. Don't regret my purchase for a second, but my wife asked if it was really worth it for her to get a CE and I said "unless you want second copies of the book and CD soundtrack, no". She didn't care about the lil' deathwing in the slightest.
oh, I suppose if you really want to gamble and hope you get a rare pet/mount from the loot card you've got that.. but really, it's a very expensive expansion if you buy more than one.
not really.. no one posted their CPU or GPU versions, and like the Tom's Hardware guide for Cata said, WoW is REALLY hard to benchmark being that someone in say Durator will have different results than someone in a 25-man raid. Also depends on what settings they are running.
looking at the cheapest MBP though, there's no reason you shouldn't be able to run it on Good settings at native rez and easily be able to keep it above 30fps at all times. turn it up to high and maybe with AA turned off and you should even be able to keep it above 30fps most of the time.