Clearly you're the "sensitive sort" like me. And that's a fine way to be nursing along these old beasts. Like I said in the video comments, it sounds tip-top to me. Your decompression assembly is different to my separate one in the predecessor Iron Barrel models in that it's actually a proper exhaust valve lifter instead of a separate little "mini-valve" atop the head, so I'd defer to the AVL experts like "Adrian II" or "Tooseevee" about that wigglyness of the operating lever. But if it ain't leaking oil, my hunch is that's a good sign.
As for those valve tappet adjustments, checking them is probably a good idea at this point--done while the engine's cool. Though I hear absolutely nothing untoward. One recommendation I might offer, which I picked up from our venerable user "Ace", who's likely forgotten more than I've ever learned about coaxing these beasts into a sweet disposition, might be to squirt a couple if ounces of that Lucas brand TB-Zinc Plus additive into your engine oil. I've been using it in addition to my own Mobil1 15W-50, and haven't needed to adjust my tappets in well over 11,000 miles. I check 'em now and then, sure, but that goo must be doing those flat tappets and cam followers the power of good wearwise. One can only hope that that those increased pre-SAE "SL" grade "old-timey" zinc levels are minimizing wear similarly elsewhere in the engine, and one bottle will do you several oil changes. Be sure not to overtighten that cover down when done with that central nut. Those AVL ones are known to crack if you even look at 'em too hard. Just hoink it down gently with a single finger on the wrench/spanner, and you should be good.