I don't see Wizard of Chicago as a mantle. Why should only Chicago get one? Where is his domain? Marcone's lands?
"Wizard of Chicago"
could be a mantle... eventually. It isn't now.
A mantle would have to be created (or form naturally... the genesis of a new Mantle is AFAIK nowhere described, neither in the canonical stories nor WoJ; but I think Harry "raising a banner" in BG is a hint both as to how a "Mantle" might form, and Harry's suitability as a foundational figure).
Demonreach is the White council's prison, not Harry's.
No, the relationship between Demonreach & the Warden is its own thing. I don't doubt the WC would love to claim it as "theirs," but it isn't.
My own WAG is that it's the other way around: the prison/well is the critical and most-important element. The White Council was created as an adjunct to the prison, and the Warden. They are, after all, a Council. By the very definition of the word, they are councilors -- advisors; but to whom? To "the Merlin?" I think not: when decisions are made, "the Merlin" gets an equal vote (much as "the Gatekeeper" does).
And i doubt Molly AND Mab can sign for him - it is likely not the individual who signs, it is their realm that they sign FOR. Biden does not sign a treaty for Joe, he signs for the US. Mab signs for Winter. Molly is subsidiary for Mab, she does not sign. The Lady signing as herself is like the Blackstaff signing for himself, not for the White Council.
Agreed. Any signatory to the Accords can only sign once; you cannot have 2 people from the same signatory.
Harry is likely still considered under two signatories, the WC and Winter. They won't give him another flag. (yes, under the White Council - recall the challenge in the deeps - even the White king said the minor practitioners landed under the White Council's sphere though they were not members of it.
Disagreed. Harry is no longer WC, they kicked him out. The WC certainly won't be honoring his signture as a WC rep under the Accords!
They are of course obligated to honor if he signs as Winter (and one of the 3 Winter Queens doesn't repudiate it).