I would love to see the in-editor documentation improved. Maybe have in-editor tutorials as well, or a book? That would be awesome.

I would also like to see a set of templates that can be used to actually develop a commercial or finished game. The examples that Godot currently ships with are very nice but all are pretty far from being a template, nevermind a real game.

As for assets, I would want to see lots of 3D props, a 3D "player" actor with animations, maybe textures and skyboxes.

Parent might mean export templates. Godot has export templates to build games for iOS, Android, Windows, Linux, macOs, and HTML5. But there are also third-party companies that offer export templates for PS4, Xbox One, and Switch.