1. "to Max" seems not right here :)
This will go off eventually, but it is not a priority right now.
2. Denoiser must have!
This should be pretty easy as long as it's just a denoise on/off checkbox in the render settings (+ some parameters for the denoiser).
3. DR must have!
I'm afraid that this is not going to happen anytime soon. There are more basic features that still need to get implemented before we can even think about implementing a DR solution.
4. material overide option is useful. We need it.
I agree, this is already on my TODO list.
Please fill bug reports/feature requests for the others:
https://corona-renderer.com/bugs (has separate login from the forum, so you may need to create a new account there)