Go ahead and adjust the valves, this could well be your problem. You might want to re-torque the head bolts as well before adjusting.
The number 3 is the big problem, perhaps the rocker is too tight and never closes completely.
Machining the head and a new gasket changed all the valve clearances. When valves are adjusted correctly, look for pretty even compression numbers for all cylinders - if one or two are off, recheck.
