Sounds like a lot of hand work for someone who has a box grader. Establish the grade where your tractor tires will run, either with dirt or 2xs and use the box blade. You can cut lower than the tractor tires if needed. All your establishing is the slope
This is all made from dead standing trees. Might shrink some but not much. Biggest reason for the "slotting" as you called it is to keep things from twisting. It shouldn't do much of that either but no kill like overkill. Lol
So to be clear unplug the cps and try to start it. I will take alot of extended cranking. When it starts it should run smoothly with no hiccups of any kind. It will be running in limp mode so power will be down. If after that checks out unplug the OS and repeat. If it won't start or has any...