My official suggestion is as follows.
Name: Mew in OU
Description A Pokemon that can take upon itself several different roles depending on a team's needs. It pays the cost of unpredictability by not doing any of its roles as effective as specialized Pokemon of that role.
So it should be able to, for example, both be a potent offensive force and a good wall (or a good baton passer, or good team support, whatever) but it shouldn't be able to attack as well as Azelf neither should it wall like Uxie or Cresselia. While I'm not explicitly saying it in the concept description, I believe it's quite obvious we're looking at a wide movepool here.
I am aware of a previous concept suggestion that advocates a mediocre Pokemon with surprise moves. I am open to comments about how similar those two ideas here and can change my concept if need be.
Now, my other point.
The existance of a Pokemon with a similar role does not disqualify a concept. Here is a perfectly legit concept:
Name: Sweeper
Description: This Pokemon should be capable of swiftly knocking out a wide variety of opposing Pokemon.
Yet I'm seeing posts like "Pyroak does what you want", "Bibarel does what you want", "Clefable does what you want". CaP project, if enough members want it, can create an exact duplicate of Clefable. I ask of the community to stop posting existing Pokemon fulfilling a certain concept as though their existance nulls the concept suggestion.
[Edit:] Oh hey. All my arguments will be from this post until I get permission to pull off something I probably won't be allowed to.
How is Fidgit capable of doing whatever my team wants it to? Kindly write down the roles Fidgit can effectively take on a team without wasting its potential. As I can see, its attacking options are rather limited and it doesn't get Baton Pass. CaP 4 must have went entirely wrong if a Pokemon supposed to have a "pure utility" role can fulfill a "jack of all trades, master of none" concept (Which, obviously, would be in part my own fault as well as the whole community's. )
Regarding your second point, let us take a look at the "Sweeper" concept. It can include Garchomp, Scylant, Tyranitar, Azelf and Lucario, all vastly different Pokemon that affected the metagame in different ways. If you rule out a concept as "-Pokemon- already fulfills -role-" you are in fact limiting the amount of new wind we may bring to the Pokemon metagame instead of increasing the diversity.
[Other edit:]
Alright, let's look over roles Fidgit can fulfill.
Team support
Team support
Team support
Team support
Quite important team support the metagame truly needed
Spiker
Team support
Yep, CaP4 was good. Fidgit works as intended. You're not listing Fidgit's roles. You're listing how Fidgit does its intended role - does it Encore a stat boost and enable a Tyranitar Dragon Dance, or does it set up Gravity or Tail Wind for the same Tyranitar? What of Trick Room for a Curse one?
Regarding my Sweeper point, you are right on that there are already existing sweepers (Other than boredom issues, I don't care what CaP did and did not make in the past when concerning new CaP projects and I don't think anyone should. ) but I was merely using it as an example. I would, for example, support a Pokemon that can ignore stat boosts (Either via fast Haze or Unaware) despite Bibarel already ignoring them.
[Next edit:]
My comment is to be taken as "CaP Pokemon must be taken as a part of the current metagame and not any differently than "official" Pokemon. " Regarding your Bibarel comment, one must note that people were even listing largely unviable Pokemon like Clefable and Bibarel.
Regarding your other point, funny how I was planning to use Doug's posts to support my own point - because that's what his posts do.
In Deck Knight's example, he refers to a "Special Wall to counteract Togekiss". Could that be construed as a general role pokemon play in the competitive metagame? No. "Special Wall"? Yes. "Special Wall to counteract Togekiss?" No. Togekiss is not a big enough threat to warrant an entire category of pokemon to counter it.
Most of what you listed either increases the efficiency of another Pokemon, ensures that Pokemon gets in safely, softens the team for it or any combination of the three. Does "Bulky U-turner" not sound a bit like "Special Wall that defeats Togekiss" ? How many players would use Fidgit in their team simply because it has a bulky U-turn and not because it is a good team support Pokemon?