Correct, I am not really approaching this in a dialectical way, I do not fervently ascribe to any specific ideology. I try to take all potential influences into account. Similarly, this does not mean human history is driven by "great men" or somesuch, only that individual decisions do have an influence on events, and should be taken into account.

I do wish things could exist in such a simple way, where states operated in such a clear-cut manner, but that's just too oversimplified. The world is just messier than that, and individual egos cannot be completely separated from people's choices.

Sure, states in the abstract do pursue their own interests, though there's a great many very small states that see their interests differently from how larger bodies tend to. This is potentially distinct from the exercise of power though, and is not necessarily imperialism. To qualify as imperialism in a way that fits empires throughout history, I think you need two things: scope and expansion. An embassy, while a means of national power, is not really focused on expansion, but diplomacy. An embassy can be a simple defensive precaution. State media can be, depending on what message it is broadcasting. If it broadcasts a warmongering message, it could easily be imperial in nature. If it's just reporting local news, not so imperial. Curbing other state media is just about stability.

Nations exist, borders exist. Whether they should or not is more up to those individual peoples that live there, and how they want to set up their societies.