I agree with most of what you say about Zelenski.
I just feel that Trump and Vance could have handled themselves more professionally particularly on the world stage.
I think the image of coherent and meaningful US leadership took a blow in that exchange.
As you now, I think highly of Trump and Vance. This exchange doesn't change that, but it was disappointing.
As to Zelenski, this article attempts to explain why he torpedoed the talks.
Obama’s Co-Conspirators Including Victoria Nuland, Susan Rice, Alexander Vindman Told Zelensky to Reject Trump Deal in Violation of Logan Act.