I love your comment so much. It is absolutely accurate and well put. I hate it when people say inaccurate statements about a real language. And I also like the idea of really trying to learn the language and use it correctly.
My two cents about the topic. I like to use real local names but I also use translations when people understand them way better. Oftentimes using them both.
I'd prefer English terms myself, though I don't mind a glossary in the back that shows the actual venetian terms.
I think this is decisive, really, names will be in English with the exception of a personal names.
My sources. being mostly historical sources in English or modern Italian sources, seem to agree that Venetian is an Italian dialect. They are, however, wrong and Ezzelino is correct. Similarly my spelling of some place names seems to be Italian or archaic, and some of them are simply incorrect, but my spellchecker which is Australian English, doesn't point any of that out.
"Names in Venetian" would be an editing nightmare.
Thank you for your reply. I find it entirely convincing.