To optimize Windows 11 for gaming, I will leave you 2 great YouTube channels that have a ton of resources on this topic.
You can adjust the RAM in the BIOS, or just leave it on Auto (default); it knows where to allocate it when needed for the GPU.
Regarding the fan whine, there is really no solution; you can report it to FW, but you might get a new unit with the same issue, as many people did. The only solution for them is to come up with an upgraded version. There are people who have taken apart the PSU and upgraded the fan, but you should only do this if you know 100% what you are doing, as you could even die if not. But there are many topics about it in the forum; check them out:
