2.7L valve cover scorching?

So I’ve been wanting to do a little work on my 03 (it’s been misfiring/rough idle). Pulled the valve cover, 5 of them broke at the head, my plan is to double nut the thread and remove it if everything goes well. Any other suggestions? Also, 3 of the 4 coil packs had cracks throughout them, I do live in Maine so it could be from heat stress. My main concern is the valve cover and spark plug tube around cylinder four. Seams to be a bunch of build up. I’ve cleaned it with purple power and replacing all the gaskets and seals on valve cover. Has anyone seen this before? Should I switch to synthetic to clean it up? Truck has 240K miles with castrol gt-x 10w-30 running through it. All the pictures relating to the problems mentioned above are here below.

 

OK, laughs.