If a retailer is selling the box full of evil, it has all the exclusives. It just means they backed at the retailer level. If your buying Mexico or the Darkness by itself it won't have any of the exclusives in the BoE
There were only 5 KSE items in the box full of evil and the box itself.
Yeah, the Kickstarter version was sold under the title "Collector's Edition" on Mantic's website and a bunch of retail stores Kickstarted the game and are probably getting it as well. They will make extras and most likely they will sell a limited amount of them if they are available. I'm sure they will all be exactly the same... it would cost more money to make a few different (take out KS exclusive stuff) than it would to just manufacture one package across the board.