Another update: Finally got around to trying my hand at a compression (wot - two people) test on Bank 1, couldn't get the gauge to hold the psi so thinking the tester has a leak somewhere - will look into that and/or get a different gauge and do a complete retest of bank 1 - but till then...
Cylinder 1 would only go up to 30 psi. Cylinders 2, 3, and 4 120+ (couldn't quite tell since I couldn't get the needle to 'stick'.
Put about 3/4ish table spoon of oil in cylinder 1 and tested again with no change.
On the bright side, new intake seals seemed to have made a difference with the plugs. ?? Cylinder 1 isn't fouled like before and by now I would have already seen a good fouling.
I did pull the valve cover off over the weekend too, just for peace of mind, and visually checked the rocker arms, levers, springs, etc and everything looked good.
I've changed the oil a few times since last October and checked numerous times in-between, never saw any abnormal qualities (foaming, bubbles, etc). Also, coolant doesn't appear to have any oil in it and is holding steady since the valley pan change.
No oil leaks from the cover, no oil in the plug tubes either.
Lastly, I think the filthy condition of the engine due to all the [ignored] oil leaks/valve stem issues left over by the previous owner is why the plug threads look the way they do. Every time I do any work I try to clean them but seems nearly impossible to get all the gunk out of those groves (cylinder head).
