As for the valve adjustment, its just like doing it on a bike. I’ve done mine twice already, every 100,000-km or 62,000-mi. It's kind of a pain because the intake manifold needs to come off and you need to develop a knack for jamming the lock-nut. The adjustment screw will enlarge the gap when the lock-nut is tightened and the gap is spring loaded (the valve spring will compress if the gap is over adjusted) to get the feel for just the right amount of drag when pulling out the feeler gauge, so that is where knack is developed. Not impossible, but you will do it a couple of time the first time you do it. So be prepared for the extra time. Not too many people have this knack…not even at the Honda dealers. My guess is that the bike tuners would do a better job, if they race their bikes.
A man's mind, once stretched by a new idea, never regains its original dimensions. [Oliver Wendell Holmes]