Again, thanks, all, for your replies -- they have lent moral support and practical suggestions, which I've tried to put to good use.
I've now accumulated over 1,000 miles on what I call the "'OldWing". And, things HAVE steadily gotten better.
I still don't really like the low-rev, engine rattle that many call 'normal' -- I may yet try the clutch-cable fix/adjustment mentioned here elsewhere -- but I've minimized it by a variety of other means suggested by some of you. And, I've consciously tried to 'under-gear ' my momentum in order to eliminate, as much as possible, 'lugging' the engine below 2,500 rpm or so. For example, I rarely shift to 5th/overdrive now till I've gotten onto steady, long-range highway conditions -- even though it's cost me c. 10% mpg, which still hovers around 42 miles per gallon.
Starting and stopping have gotten better -- but, frankly, there are limitations to how smoothly I'm physically capable of stopping or starting a 1,000-pound-plus (with rider, or two!) machine with grace and aplomb! It might take a new(er) bike to eliminate all drama. I suspect finding a way to solve the aforementioned, 'normal' engine-rattle noise and 'lugging' would go a long way toward making starting and stopping routine, but I haven't figured either out yet :builder:. And, no, I'm not willing to accept that 'normal' engine rattle is normal, even in an old bike. Sorry. Something's not right, or it wouldn't sound like that!
Still, the overall performance seems sound enough to trust it for moderate purposes. I'm neither sure that this bike would, or would not, survive a cross-country trip, for example. But, I don't have much concern about the next 50 miles on a daily basis, and assume that something will clue me to be concerned if I need be.
So, I'll keep changing the oil and other fluids every 1,000-1,500 miles or so (even it that's overkill!), and swap plugs every new riding season (even though I've added ones that ought to be sound longer than that). Whatever else presents itself will be judged by its criticality. Someday, I'm sure, I'll just decide it's time for new motorcycle!
My biggest, immediate concern is convincing my occasional riding partner that she suffers no real danger from the bike falling over onto its engine and luggage guards -- as it is wont to do occasionally, when circumstances conspire to make 1,300 pound or so of machine and human too much for my left leg to keep erect. :shock: I'm open to suggestion... :?