When I refer to https://doc.ez.no/display/PR/%28n17%29+-+Languages+and+Translations, I am thinking that if I don't check the radiobutton " Base this translation on an existing translation", my content edit should start from an empty content item, but this does not work, it seems like it's always basing the new local version on the main version.

Another issue is that, reading the spec, I'd expect to be able to see both the edit fields, and the reference value in the other language, but this is not visible.

It's not blocking, but at least, it should be possible to start from an empty object.