Yes, the 500+ references to princes in "The Law of Nations" show that Vattel was willing to entertain various flavors of monarchies, not just the "very English" variety. The man talked a *lot* about the role of a monarch in relationship to his nation, and the role of a people to their monarch.
How the Founders could have relied so heavily on Vattel, yet so roundly rejected his copious writings about sovereigns and princes being the default and most natural governmental arrangement, will just have to be a mystery.
A disengenuous reply. The Founders themselves were in the process of roundly rejecting sovereigns and princes, and so of course they would reject it. What's more peculiar is, you seem to think this is somehow a bad thing pertaining to Vattel, but you persist in advocating Blackstone as the source for understanding U.S. Constitutional requirements for the Presidency, an elected office. Not hereditary.
What did Emerich de Vattel have to say about a Constitutional Republic? A great deal. Compare and contrast to Blackstone. What did Blackstone have to say about it?
What was the sentiment of the people, at the time of the Revolution and the time our Constitution was written, regarding English claims of citizenship over them, as feudal subjects in permanent, irrevocable allegiance to the Crown?
You seem to think they were so happy about it, that they sought a continuance of the very law that they revolted against.