all money is by definition the result of exploitation.

certainly not all, but like, a major amount of the US' economic prosperity does come from that. In some other countries it's an even bigger fraction, in some it's much less.

I still don't see why that makes taxes going towards good things instead of bad a bad thing if those taxes weren't the result of exploitation.

That "if" is doing a lot of work here. I agree, if the US economy was free of foreign exploitation, if we traded on equal footing with other nations and did not interfere in their affairs, and weren't coasting along benefitting from several lifetimes of doing so historically, then it wouldn't be odious to build a welfare state on our tax dollars, and there would be no added structural incentives to start doing imperialist exploitation. But that's a big if, and if we had a magic button (or, sufficient political power) to get rid of imperialism, we could probably do better than just social democracy.

I'm not opposed to welfare states in principle, but I'm going to be a lot more supportive of one in the periphery than the current imperial core for all the reasons I've been laying out.

Frankly I don't know what the path to socialism in the imperial core will be, but it's a lot easier to imagine it involving a transitional period in which the spoils of imperialism are lost by some outside mechanism amid declining global influence, and the nation having to make a choice between declining living standards vs maintaining capitalism, than to imagine a scenario in which the spoils of imperialism are used to build a prosperous welfare state that then abolishes the source of (a large percentage of) its own funding (aka imperialism).

And doing social democracy with taxation has nothing to do with "getting the means of production". It's forcing a concession, at best. But I agree that a straight up uprising in current day US is not likely to succeed (though that may change as conditions worsen).

Social democracy as practiced in the west just entrenches capitalism, and leaves the door wide open for any gains made to be clawed back. I won't say it's a bad thing, it helps (some) people, but it isn't my goal, nor part of my vision for how we get to communism

If we had the political power to get rid of or reduce imperialism, a good place for the profits of that stuff to go is back to the countries we stole it from. That would just be pulling out the knife, helping them develop their own productive forces and independence would be a start at healing