As stated before, use a sealer on the gasket. That will take care of all the seal problems, and doesn't take much. I had to tear my bike back down after putting it back together after a valve adjustment for a tiny oil leak at the gasket that a thin coat of gasket sealer would have taken care of the first time. Removing the flies is an easy thing to do if your already in there, and gives better throttle response, at least for me. No tune needed. A good flushing of the radiator with water should be sufficient, I just flushed and back flushed then used premix on my bike and she runs well like that.will do the valve clearance, just got a nice tool from snap on for that, and coolant flush sounds nice, and what is good for cleaning the radiator?? . what about replacing the plug hole gaskets.? I hear riders taking their secondary flies off, would that mess the bike up?? and will need countless hours of tuning to correct??
Dude...get a torque wrench and call it a day. Your Suzuki friends can blow off....pull the cover off, clean and dry the gasket, put the cover back on and torque to spec. Done....'nuff said...the head cover may just need to be retorked, i am doing all this maintenance now while all my plastics are off, even though the valves sound fine and the coolant looks new, its good to get it out of the way now, wont hurt to check the clearances. the valve cover is starting to leak a lot now it looks wet on the shifter side corner of the cover, and that irritates me. I am OCD. I don't want one of my Suzuki friends to point it out.