Interesting read on the zinc, I may do more research when time allows. As far as oil, I've run Valvoline 10W-30 in mine for the 12 years I've owned it, based on the recommendation of the MC mechanic at the time. No oil related issues so far...
If you ask 100 people about oil recommendations, you'll probably get 90 different answers, and there's a very good chance that all 90 will work just fine.
Oil related engine failures (other than low level or pressure) are extremely rare, not sure I've heard of even one on this board ever.
1989 ProStar 190 with "Safe T Top", 351 Ford, GT 40 heads painted Ford Blue, Elec. Ign, 1:1, 720 hours, 4 blade prop, PP 6.5, removable platform brackets, custom color from factory, hot water shower, Boat Buddy & LED lights on trailer
2010 D3 Z7, 2 @ 32 off, 34 mph so far