Native file dialogs would be nice, agreed. Same for drag and drop support. The great thing about Godot is that it is, after all, "just" an open source application written in C++, and if someone wants to add support for this badly enough it is definitely doable, especially if you limit yourself to just one or two platforms.

As for menu bar, why do you think a native one in particular is better? Godot has great support for menu bars already, and I'm just not sure what the native one would add to the table.