There is no other method to verifying the valve clearances are in spec. You must physically verify the valve clearances with feeler gauges. As others above have said, it is not a big deal. Valve cover is 3 bolts, just make sure you clean the dirt out of the pockets they sit in before reassembly.
As far as the "if it ain't broke, don't fix it" comment. Well, there are 2 schools of thought. Preventative maintenance or subsequent maintenance. Preventative is cheaper 99.9% of the time and much easier on the mind.
