I don't think it's fair to compare US foreign policy to actual imperialism as practiced by the Soviets, the British, etc. The US does not maintain colonies, and, as you point out, does not even attempt to exert total control. Pursuing your interests and forcing total political and cultural domination are not equivalent. The US is more than happy for Germans to be German, Japanese to be Japanese, etc, as long as US interests are prioritized. This is clearly not the case for other major powers.

Nations (and people) exist in an ecosystem, and so will always behave accordingly, and always in their own interests. There are some emergent properties of ecosystems, one of which is that optimal behaviour is to acquire the maximum you are physically capable of defending, not the minimum that you need to survive.

It's perfectly reasonable for the US, the big fish in the pond, to leverage its advantages accordingly, and to the maximum. It would be a disservice to the US people if it did not. Smaller fish should indeed be glad that the big fish is as placid and strategically (rather than ideologically) motivated as it is, given the historically experienced alternatives.