I think y'all're underselling the Philippine Republic, especially Lardo. I do like Lardo's idea of changing Mckinley's mind, though.
Tell me, if the world's so separatist, why did those thirteen quarreling colonies hang together? Or Japan? Or Canada? Or the UNITED Kingdom that crossed the water? Why's Europe getting CLOSER? Why didn't Iraq break up like half the pundits said?
There would be rebellions, of course, like our Shay's and Civil War. But, federal democracies are pretty good at putting them down. OTOH, it might've also gone in and out of dictatorship as IOTL.
Democracies are also the best at tech, and so they'd likely modernize well.
IMHO, the most rational US-Philippine deald would've been for basing rights in exchange for American agreement to defend them from external attacks; of course, most rational has a way of being rare in the real world.
Two points:
a)Iraq does not break up mostly because it is not allowed to by anyone in the area, and AFAIK the Americans are not willing to encourage it either, whatever the neocon agenda might have been.
Iraq is not allowed to split basically because in the local politics as I understand them, a split would cause a mess. It's not like Iraq is made of discrete territorial/historical entities with some internal coherence. There were, and maybe there are still, very harsh clashes about the Kurdish or Arabic pertinence of some areas, not unlike the troubles some former Soviet areas are into because the dictators had ordered massive deportations (horrible simplification here) and displaced people claim the areas they (or their parents) are from as national home.
A partition of Iraq would be a mess, and would also mean a Kurdish state of sort, that is warrant for future WORSE mess in the current situation.
b) In 1898, no colonial power saw people of the Philippines as even remotely equal to "Aryans". (And actually there was a number of white people who perceived being "Aryan" as a part of their identity, if not the foremost part).
So there would be no much care about whether Philippines are ruled by the most ruthless tyrant or a decent approximation to democracy. "Aryan" so called democracies of the time, the few that were, did not care at all.
(I say called democracies for in most cases, there was no female suffrage. So half the adult population was forbidden full citizenship. This does not fulfil my idea of what a "democracy" is).