I'd worry more about the difficulties inherent in the deck than about hosers. From what I've seen, Domain hasn't managed much in the way of "top tier" performances, but some folks have worked up some pretty good designs. I think it could still find a few good finishes before November.
The difficulty is that there are counters in T2, more than in IBC. Domain tends to be a deck that only has a few key spells that need countering as it is forced to play so many mana fixers.
Domain will have serious problems making the transition to Type 2. It gains Rampant Growth, and that's about it. And it finds itself facing a field of Blastoderms, etc... There are an enormous number of good cards not in IBC, and Domain has to face all of those cards when it makes the jump to Type 2. Challenging, indeed.
There are so many ways to hose domain decks because they need the basic lands to work. Get rid of certain basic lands and the deck will probably stop functioning.
5 color decks are a bit different. Like Cateran Emperor said, you just need to be able to produce the colored mana. It doesn't matter what you use to make it. Plus, you can do so much with five colors. I made a deck with Legacy Weapon, and when it gets active, there is almost nothing that can stop it. The good thing about it is that I can produce any color mana with Birds of Paradise and Utopia Trees and if I need to I can use Cities of Brass and pain lands.