You all view it very much from a legal/constitutional POV, without including the moral and political aspects of the question.
I doubt anyone here would argue the moral right of these territories to self-determination.
The US has together with France kept far more of its old colonies than any other nation.
Ahem.
British Overseas TerritoriesI think at least West Samoa and Samoa should ideally be reunited.
As the 1969 referendum concerning merger of Guam and the Northern Marianas shows, mergers that seem logical to outsiders aren't always approved by those on the ground. Still, if they want that, I'd be fine with that, but I'm doubtful that American Samoa wants to turn away from the US and towards New Zealand.
Guam and Northern Marianas are also too different from the US to be "American" in any meaningful way.
I fail to see how they are more different than Hawaii was at Statehood and I doubt anyone would argue against Hawaii being American. Indeed, while it would be smaller than I would like for a State to be, I would not object to a combined Guam and NMI becoming the State of Mariana (or whatever other name they like) and the 51st star on our flag. While the 1969 referendum indicates there likely would be some opposition to a merger (Guam rejected it for what can be seen as one of the most American of reasons, a fear of higher taxes), I'm reminded that the Oklahoma and Indian Territories were willing to accept a merger when given a choice of remaining two separate territories or becoming one single state.
As for the remaining inhabited US territory, perhaps we should return the Jomfruĝerne to Denmark?