Kernel task - Memory Usage

as long as you are running a commercial AV you can expect mixed results on your kernel process. It's your prerogative to run AV on the mac but the consensus around is that they have been documented to cause massive problems with interoperability in OS X. And if you disabled it that is not an uninstall so you can't use that as a barometer to measure the change until it is completely uninstalled from your system.

There are no mac virus at this time an no mac AV has ever had to prove itself as a prevention against theoretical attacks. If you are using them to protect your Windows computers use a Windows AV solution on a Windows machine, not a Mac AV as the gatekeeper because it's about as effective as the guy who guarded the gate of Bree in Lord of the Rings when the Nazgul run him down and trample him to death with their horses.

I'm not entirely sure what would you like explained, but even if they were identical systems with identical software you will see deviations on how they behave once a user does something specific, and that's not even the case in this event. All systems are different due to mitigating factors.

If you would like the volunteers here to look into further analysis of your system you are welcome to post an etrecheck report in this thread.

And if I explain this machine to the Godfather, will he owe me a favor that he can not refuse on his daughters wedding day?

because I could use an espresso and one of those cookies with the bird seed all over it right now.