For example, third worlders are breeding like rabbits and due to their lower average IQs it's difficult for them to be self-sufficient, both factors leading to mass-poverty and starvation, which in turn makes them mass-migrate to white nations

Won't they just stay in their own countries and starve if we have proper ethnostates though? The only way they are allowed to immigrate is when anti white genocidal Jews sneak into power positions and let them in (which theoretically wouldn't happen in an ethnostate). If whites controlled our own countries we'd be able to propagandize our populace into not getting duped by third world suffering. The only reason millions of whites want to open their arms to these third worlders is because of Jew propaganda.

If we could take back control over those third world nations, we could impose legal restrictions on the amount of children they can have so their economies and infrustructure become less over-burdened,

If Jews are still around they are just going to reframe this as 'evil white genociding the poor brown people' and they are going to attempt to divide us and get other countries to attack us for our troubles. No good deed goes unpunished. Your proposal reminds me of the 'white man's burden' argument. We all know how that turned out. Do you really think that we have the magic touch to stop third worlders breeding? Only nature can do that in my opinion and we should let nature run its course.

because if we refuse to take power, another race or civiliaztion will anyways

Maybe? However, if whites are truly as strong as we think we are how is it that another race and/or ethnic group will really be able to dominate the world without our approval/consent?

And I disagree that it's inherently hypocritical for us to desire to be the ones in charge,

Agreed. It's not really very feasible right now though. If whites desire to 'manage' the world in a healthy way then first we need to FULL control of our homelands first and secure them. We are not in a position to debate who should run the world when the Jew and their allies are fast approaching total control.

I think the Jews will just remain in that position, and if we manage to remove the Jews from power but then refuse to claim it ourselves

How do you propose we remove Jews from world power? Don't you think that's a more pressing concern than who will control the world after Jews are out of power? Is there really any doubt who will control the world if Jews decline in influence?

But on an individual level, I still generally agree with the NAP. If a white person assaults, tries to rape or murder, or tries to steal property from a Jew or a black person, I think the Jew or the black person should have the right to self-defense

The NAP is a terrible argument because it hides the real reasons why humans attack and murder each other (religious, political, social and general group dynamics behind almost all violence). The NAP essentially ties the hands of anybody who internalizes it and the only people the internalize such an ideology are whites. If you really want whites to control the world they're not going to be able to do it with one hand tied behind their back.