I think your opinion on him not wearing a suit is valid. When it comes to human behavior and cultural norms between people, such things are subjective, everyone has a different opinion and there is no true rule book to life, so right and wrong become value based. As such, simple words and gestures can be very offensive to different people. I accept his reasoning for not wearing a suit as being a sign of solidarity to his military. Others do not, obviously. Such is life.

To clarify, I'm not saying that the US should thank him, just pointing out my confusion why Vance made such a big thing out of it given the deal that the US is asking for is $300 billion in backpaymemt for past support and an additional $200 billion with no guarentee for future support from the US. The Ukraine was asking for future support and the US wasn't confirming that, so whats the additional 200 billions for - interest? To be clear, this isn't an act of good will the US seems to be treating it like a loan. That's how it appears to be at least.

Zelensky was referring to 2014 when Russia annexed the Crimea.