I think you're right about a lot of what you said, but I think Sableye has much more potential with the B&W new rules than you're giving it credit for. A huge part of the reason donk decks (or just decks with the potential to donk) don't manage the donk everytime is precisely because they have a 50% chance of going first every game. Unless these types of decks have some unbelievable opening hand (or they can hit weakness on a low HP Pokemon), going first is generally bad for them since they can't play trainers, supporters, or stadiums. Going first and hitting for 20 or something gives the opponent a chance to play a Pokemon Collector and get a bench going. Going second, which is generally good for donk decks right now, gives the opponent a chance to use Call Energy to get some Basics on the bench as well.
Imagine, however, what would happen if first turn trainers, supporters, and stadiums were allowed. Going first becomes awesome for donk decks. It means that the opponent gets absolutely no chance whatsoever to get Pokemon on their bench (no Call Energy, no Pokemon Collector). Now, you may say that half the time, non-donk decks would go first and use t/s/s to get Pokemon on their bench though, right? Well, that's why Sableye would be absurdly powerful, as it's Poke-Body steals that first turn from the opponent. Imagine playing down an active Luxray GL and a Crobat G on the bench (just to avoid the donk), calling the coin flip correctly to go first, then have an opponent open with a Sableye, use Pokemon Communication to get Uxie, drop a Crobat G and a Basic Dark, drop Uxie for 4 cards, play Expert Belt, play a PokeGear 3.0 for a Seeker, drop Crobat G again and KO Luxray GL for the game. Seems pretty messed up, right? Imagine what newcomers would think of the game if it played out this way. "Wait, how'd you get to go first?! Hold on, why do I have to pick up my Crobat G? You mean that's game?! Wow, this is stupid..."
In a format where going first provides such an easy way to win, you can bet that people will take advantage of it. And Sableye breaks that 50% chance of going first. Of course, more players will be playing Sableye, so things might return once more to the 50% chance of going first. But then it would just be donk decks playing against donk decks. This, to me at least, seems like a massive problem.
Of course, simply absorbing B&W cards into our format without adopting the new rules puts a huge blanket of uncertainty over the format as well.
I'm in no way denying that donks wouldn't, as you say, become far more likely with the BW rules. However, I think that your example is a greatly exaggurated one, as it would be with a deck that wins via donk or not at all (not to mention that that's a LOT of specific cards to have on turn one ALL THE TIME). This kinda goes back to what I said before; You won't always get the donk, just as Sable-lock and Vilegar don't always get their respective Sableye and Spiritomb starts, even with four copies. It doesn't matter if your deck is built around donking WITH the rules in your favor. Even with an 80% chance to donk as oppose to a 50% chance before the rule changes, you still won't always get the donk. When you don't get it with a donk-only deck, it's an auto-loss. Those kind of decks, while frustrating for the skilled-players who DID lose to it due to bad luck, won't win Worlds, regardless. The only competitive deck with Sableye that I can see getting a tremendous boost from the BW rules is Sable-lock simply because it already has the capability to donk AND disrupt AND carry out longer matches (meaning it won't auto-lose without the donk). It won't need to make any changes to its deck structure to take full advantage of the new rules, meaning there's no inconsistency in going for the donk to begin with.
Now, will the BW rules w/ Sableye be annoying as hell? Will it have great potential? I'd be a fool to say no. Of course it'll be annoying and frustrating. Then again, anything that P!P does with BW's release is going to be frustrating and annoying. The skill/luck table WILL become unbalanced, regardless of what they do, and that's what so many players are in a ruckus over; it tilts the odds too much towards luck because of, like you said, the inability to even TAKE your first turn. Never-the-less, it still won't make Sable-donk the Worlds winner. The true winner will still be one of the current top tier decks, still; Luxchomp, Dialgachomp, Vilegar, Sable-lock, etc. Personally, I can see Sable-lock as the most probable victor for reasons explained above, but this is just theory. Whether I've guessed right or not remains to be seen. Only Nats and Worlds will settle the debate.
As for newer players, pardon me for saying this, I don't believe that they should even BE at Nats/Worlds if they're just starting the game, so they won't really feel any of this considering that all this drama will end after Worlds, anyways (in other words, it'll last for what... 4 months, tops?). In fact, next format will be a bit of a blessing to them since the format will be slowing down. Many current awesome T1 decks will simply not exist come the next format. The only donk-possible deck that will be available is the Pachirisu CL, Zekrom, and Shaymin UL combo deck (all searchable via Pokemon Collector), but even they won't get the donk if they don't have three energies in their hand by turn one. If any well-mannered player DOES face a newcomer, it should be emphisized that said annoying donks shouldn't happen near as much once the next rotation comes.
Donks will be annoying, but rather that concentrating on the negatives of all of this, we should be grateful that our next format won't be plagued by the same fate. I'm sure P!P knows this, too, and that's kinda the main point I was trying to get across in my first post; Rather than get all bummed out over something so short-term, try to look at the big picture and realize that the game's future health won't be jeoperdized after the rotation. On the contrary, the future is very bright, and it will allow players like myself, who started the game well after the E-Reader era, the oppurtinuty to experience those "ancient set-up decks" of the Base-set era.
Besides, from what I saw in the GG-dominated format of 3-ish years ago, anytime there's a generation shift, isn't there ALWAYS some form of imbalance due to new cards/rules? If so, then this year is no different. It's a just generation shift. Its negative effects will be long forgotten come next format or two.
