Ah, I've been waiting for this for a while. It's obvious that the majority of people don't like Baton Pass, and not just facing it, most tournament players despise the thought of using it, because you are considered to win uncleanly, unfairly, and are disrespected by your peers. The question is obviously whether there should be some method of reducing or eliminating the uncompetitive aspects of it, i.e. the parts that allow a less competent player to beat a more competent one, in the same vein as Swagger. First I am going to answer the questions outlined in the OP.
- Is Baton Pass (with specific reference to full Baton Pass teams) a problem for the development of the metagame?
It depends on what you mean by development. If you were asking about whether it affected the health of the metagame by being a strategy that allows worse players to beat better players without them having a controlled chance for themself to win, then the answer is most assuredly yes. If you mean development as in, a metagame adapting and evolving, then I'm not quite sure. Hypothetically, if everyone used this strategy, then obviously it would hinder the growth of the metagame. But are the group of people who can be referred to as "ladder trolls" really affecting how the metagame changes? I'm inclined to say no. What the question should say, is if it gives an inherent advantage towards worse players due to the better players having no control over whether they can win or not, regardless of skill level. I'd also like to make an interesting point: it is ridiculous to say running a specific counter to something in order to win against it, such as Taunt Thundurus for example, means that the strategy is not uncompetitive. The question is, in BW, if you didn't have a check to Rain Offense you'd lose. We need to define the line that makes these two scenarios different. Is it the amount of checks available for each playstyle, or is it the skill involved to execute that playstyle effectively?
2. If so, what elements, in particular, do you think are pushing Baton Pass over the edge?
Aha. This is also a interesting question. If we assess the individual aspects of Baton Pass, you have the move, a Speed Boost user, Espeon, Mr. Mime, a defensive booster, both physically and specially, and the move Stored Power. The combination of each of these makes this strategy broken; if you got rid of one it would still be able to function (the obvious exception is Baton Pass itself, but I'll get to that). Lets analyse whether the strategy would work if we banned each thing individually, and also what would happen to to other playstyles, ignoring complex bans since there are so many possibilities for that that I will address in a later question. Starting with Baton Pass, this is the main offender, so we can easily say "if we get rid of this, full Baton Pass is no longer possible". However, to answer the second question I posed, how does this affect the rest of the metagame. Well, quite a bit actually. In BW, many people used Baton Pass on Celebi to escape the Pursuit of a Tyranitar. By banning Baton Pass by itself, this becomes obsolete. Another ramification of banning Baton Pass is that we eliminate the "Quick Pass" strategy, where a Pokemon such as Gorebyss, Smeargle, or Venomoth would use a stat-boosting move and pass the boost to a teammate, which would only work once, and it would allow that teammate to attempt to sweep. Therefore, I am opposed to banning Baton Pass by itself. Now for the rest of the possible things to ban, I am not going to talk about the effects that that would have on the metagame because every single other user of those aspects for any other reason would be unable to use it anymore, so I am opposed to banning those things by themselves as well. Lets instead see how Baton Pass would work without those factors. Without a Speed boost user, you would still be able to beat slow, stall teams, and if you manage to obtain a Substitute, a fast opponent isn't really an issue while you KO it. Without Espeon, BP will still wreck teams without a phazer. Without Mr. Mime, BP would wreck teams without Perish Song. Without defensive boosting moves, you can still get enough boosts for Stored Power to be powerful. Without Stored Power, you increase the reliance on offense boosting moves, but you don't stop Espeon from being able to just use Psychic or w/e.
3. Do you believe that banning individual Pokémon (such as Espeon/Scolipede) would make Baton Pass manageable?
It could potentially, but it would limit other strategies with those Pokemon and the issue may still be there as I've sad above.
4. Would you support a blanket ban on the move Baton Pass?
No, again for reasons above.
5. Would you support the introduction of complex bans (like Pokémon X+Pokémon Y on the same team)? Feel free to suggest more forms of complex bans, of course.
Yes, as this is the only way of actually nerfing Baton Pass, but it would take a lot of effort defining which combination breaks Baton Pass as a strategy
Overall, while I want BP gone, I can't justify a way of getting rid of it without limiting other strategies, aside from a complex ban, which would need to be something like "[Mr. Mime + Baton Pass]+[Espeon + Baton Pass]+[Ninjask/Scolipede/Combusken + Baton Pass] + Stored Power". If we can find a simple way of getting this gone, then good. In fact, I might be fine with a blanket ban on Baton Pass if we think that getting rid of BP is much better than BP'ing out of TTar with Celebi, but I don't know if we should.