Re the second aspect of the elements panel being visible. Where it feels like a bug is that as an “edit access” user you can select things in it, drag them into the page (yellow highlight to see where they are going to appear like normal) but then they disappear and are not editable. That would cause severe frustration for a user. Also the structure panel is locked down so there’s no indication of what happened. As soon as you navigate to any content you never see the elements panel again and there is no “+” button to reach it. That’s going to feel confusing and broken to users.
I’ve got loads of thoughts about how editing modes in the the builder could be managed better that are definitely in the the feature suggestions category. however this one just “feels” like a bug even if technically it isn’t.