Gooz, TTT is trying to not spoil what should have been the true story he wanted to post, but I know he has in mind something "resembling" the hidden, underground headquarter into an inhabited island that you are proposing.
The point is that "NOW", without a company, or an official purpose, and obliged by the UN not to live the island, the Vanguardians have to adapt to La perdita as people, and not as members of a team.
So, while the need for a headquarter, especially for the heroes you mentioned (and also Edulcore, I guess I could add), is true, it would be beyond the necessity of this story. By the way, this new way to find accomodations for the characters, descends mainly from how the "monitor room" of the Complex was built: right in the sleeping room of Grissom Montag!
So, I picture that the armory of Vanguard will be in Phil's villa, and the training room at Priest's home. Altough we never had (or had shown) a trophy room, that could go right in Euro's home.
This sort of thing...
I think now the fun would be to see what the Vanguardians will choose as houses, and, the non-wealty of them, as jobs.
Just when the new purpose of the group will be estabilish, it will be the moment to give them a meeting room. For now, IMO, they could rotate into the living troom of their various home.
