??? Blender has scripting but it's for artists... Like, artists make movies with it... Movies that have scenes with dozens of artists working on it...
At least when I last tried Blender the UI was a lot harder to use than something like Unreal or Unity editor.
I'd probably look at the Godot editor first.
But I do like the idea of trying to find an existing editor in the same domain and modifying that rather than building from scratch.
The demands of a movie differ from a game which is why I'm a bit doubtful. But nothing is impossible to achieve with peope planning, so I'm not dismissing it.