They won't burn up but they will create some unnecessary friction if they are too tight. That is usually the noise you hear when you are in need of a valve lash adjustment. If they are too loose, the valves aren't opening far enough, so power losses are noted. The procedure you describe is right. To make sure, the cam lobe should not even come close to the rocker arm pads when you are adjusting. Sounds like everything you are doing is right, so at this point, adjust to spec and see if there is a notable difference in sound/power.