aveo misfire idle new engine

[chevy24rr]

I have a 2004 aveo, had the engine and valves redone recently. The shop reused the valve cover gasket and caused oil to leak into the spark plug wells. That caused a misfire, but after a new gasket and plugs, I still get a rough idle and misfire code. Only idles rough, under rpm, runs great. Also has a very small knock at 2,000 rpm....SOMETIMES. I'M SICK AND TIRED of these idiots telling other people with the same problem what its NOT. well duh, I know its not the left rear wheel bearing! It's not the maf sensor.....I know this because they don't use one! Spark plugs DON'T leak oil, mainly because they don't hold back oil! These people need to shut up and go back to world of warcraft and stop giving advice.
If any REAL technician has advice, please help. I am a certified motorcycle technician and have COMMON SENSE, unlike many other forum posters.
Ok the problem is random misfire, very rough idle, about a top fuel dragster. I have fixed the valve cover gasket and all plugs with ngk, so no more jumping spark. Still get misfie code, I know coils RARELY fail and I don't have any exhaust leaks, and compression is good on all cylinders. I almost think the timing is off, but checked that when the cover was off...timing is on, close enough to not idle poorly. You techs know what I mean. I say techs because we are TECHNICAL not just mechanics. Anyone can pull a motor, but a tech can put one together...without you knowing he was ever in there. I know some of the posters are just trying to help, ok, but please leave it to the professionals to give advice (at will). These forums are all flooded with dead end responses. Sorry to complain so much, now my fingers hurt from typing on this phone, and I have a headache.