Kilrah

Earlier ones no, but Windows 11 wants at least an 8th gen on the Intel side, and all boards that can run an 8th gen do.

You might need to prepare the USB / install to it in MBR/BIOS/CSM mode instead of GPT/UEFI, or vice versa. Well you're 2 USB drives into it and it still doesn't work, a $20 SSD would have been a better purchase

As mentioned very likely a settings problem. If the display isn't told to display full black it won't do so.

QD-OLED's generally better than OLED so the error would be in your favor...

Ditch the AMD card, there's a reason Nvidia is taking the whole AI market... More seriously, get yourself a $20 256GB SATA SSD to install linux on. Usually on mobos you can choose separately for NVMe and SATA drives whether they should go through the RAID controller or not, so you could keep the NVMes there but disable it for SATA drives. Check if it's the case on your board, it is on Intel but I don't know how it is with the AMD version. If not then ditch the RAID altogether, RAID's not beneficial performance-wise on NVMe anyway, usually the opposite. If you want to group drives to avoid separate volumes take the middle option, keep the boot drive alone (can have both Windows and Linux on it), then group the other 2 in storage spaces.

No. Just draws lots of extra power and has artificial limitations like concurrent number of streams that the iGPU doesn't.

For Plex use better to favor Intel CPUs with iGPU, 7th gen and up. That supports everything you'd want.

Why even install a server's OS to a USB drive? Last thing you want to be using for performance and reliability.

Because it needs to be powerful when needed. But PCs are used for lots of things, and that need may only be present 10% of the time it's powered on, and having it draw double the power when not necessary makes no sense. Balanced, again no point switching to high perf. Every Windows user is on Balanced unless they change it, while some may have issues there it'll be a tiny fraction and if it happens it's only revealing that there's a problem somewhere else that is what should be fixed.

Sleep mode, so all of that is flushed and drives are in standby already.

Balanced is standard. High performance will keep the CPU at full speed not allowing it to clock down. Almost zero benefit outside of benchmarking where you might want to eliminate the tiny delay between something needing horsepower and the CPU speeding up to give it, but at the cost of a significant increase in idle power draw. My 13900K draws about 30W in normal "idle" in Balanced mode, doubles to 60W in High Performance from clocks going from average 2GHz to 5.7... If you have instability on the Balanced plan there's something very wrong with your hardware/BIOS settings.

Hardware won't care, software will vary, obviously anything unsaved is lost but there shouldn't be corruption beyond that.

Molex always, SATA isn't meant for carrying much current. SATA max 4.5A on 12V, Molex can do 10A. Also you can't just expect the card to take 75W from the PCIe slot. That' said you're above the rating of the PSU, it can only give 230W on 12V which is what all major components are drawing from.

If you only want to switch USB then use an USB switch and not a full KVM.

So you're trying to WoL over Wi-Fi? Yeah that won't work. Use wired ethernet.