Some of these things should be easily possible and may be implemented. However due to the fact that things like render settings are held in nodes and will likely be duplicated from project to project, as well as the fact that renderer and camera connections can vary dramatically, setting up an "overide with defaults" system would probably be difficult. Essentially you would need the project loader to determine a camera to attach the render node and chosen settings to. Alternatively you could have it just override render settings in one of the project's renderers, but again choosing which one is the difficulty. Imagine for example if someone decided to added a few extra cameras and render nodes for their scene. How does the loader know which one to override or replace? And if you just add, then you lose the camera position someone else setup, which may be an important part of their scene.
This doesn't mean something along these lines won't be implemented, but the difficulties involved do lower the likelihood somewhat.
- Oshyan