Just to reiterate - this isn’t about what settings are ideal for good renders / beginners, or which settings are important and which should be ignored.
The goal should be to have ONE streamlined UI that presents beginners and experts with an intuitive and user-friendly experience to control V-Ray’s sampling.
Possibly the most important consideration in building this UI is that it does everything it can to ease the transition from beginner to expert.
So to elaborate the Basic / Advanced mode idea:
Basic mode could hide all sampling controls and be left up to Vlado and the team to optimize as they see fit with each version of V-Ray. Possibly only Noise Threshold and Time Limit remains exposed and constant to the user, with a few additional options like Bucket or Progressive rendering. This way new users can easily start in V-Ray, hit render, and get a good looking image quickly without getting bogged down in the sampling parameters.
Advanced mode would reveal sampling controls, but still present them in a way that would be easy for a user to transition from Basic level to Expert level in a day’s worth of learning. This allows people that want to become more advanced users of V-Ray to easily transition once the time is right. Again, intuitive design is key to making advanced mode easy to use and understand - without having to read countless forum posts or tutorials. I believe this IS possible.