3] What is the difference between Kernel and User mode on Windows 11/10? The biggest difference between both modes, really, is the level of privilege they offer.

The operating system mode. Processors operate either in kernel mode or "user mode." Also called "supervisor mode," the kernel mode enables the OS (kernel) to execute "privileged instructions ...

perfmon says that 'Kernel Current URIs Cached = 2 (average) and that 'Output Cache Current Items' = 3000-4000 (average) I think that this means that almost all of the objects are in the User Mode ...