Intuitive? I'm not sure. Its still got a learning curve. When you say "inspired by modern browser's dev tools" and given the HN audience I was expecting something that didn't hide the actual HTML as much. For example the element picker in browser's dev tools will show the tag name as the title when you hover over an element vs you abstracting it away to things like "Text" which then have a "Text tag" which has you select a human readable definition of the tag.

Is this dev tools inspired or Wix inspired? It feels more like Wix than dev tools.

Is any of that bad? Maybe not but its what I (because of my background) was expecting; something closer to HTML because there isn't an onboarding story and dev tools was mentioned. I think you need an integrated tutorial as part of the initial experience. Either tutorial overlays or maybe replacing the lipsum with instructional text, something.

The publish site feature, its not well explained what that does. I think some users would expect a site builder tool to be able to provide a zip or even sftp the pages somewhere. I think the only option here is to host with your service but it should be spelled out. Again, probably related to having the editor as a starting point with no on-boarding.

It seems like a slick tool. Basic page editing doesn't seem challenging. I think to really test it would require that the tester build some complex sites with the tool. Consider paying for testers to do that along with post-build interviews. It might help identify workflow issues. If you have some free users building complex pages maybe just offer them a free upgrade if they'll let you pick their brain on a zoom session.