Depends on your stock, the pedigrees, your experience, and so on.
Although, at 2 weeks you can say nothing about their characters. And I guess pretty much all breed specific points of interesst aren't developed either, some may, like colours, but the only thing I see at 2 weeks if something is seriously off. (I only breed mutts though, so no expert on breed standards)
Nope. You need to wait until the body develops more. 12 weeks, or 8 weeks at the earliest, is when I start looking at type. If somebody is selling a rabbit as show quality for younger than that I wouldn't buy from them.
Yes because breeders can determine if the rabbit is a showable color, and if it has good lines / is pedigreed. Certain colorings or markings are not showable.
No because good type will need to be assessed when the rabbit is older (5+ weeks, in my opinion). No breeder can ever guarantee the rabbit will go on to win shows, but using the word "promising" is a very good sign (if the breeder knows what they are talking about) and most likely the rabbit will be good type when it grows up and into itself.