I can't tell if you are considering/comparing an FJR and a N1K or an FJR and a BMW RT. You state FJR and RT are your two choices at the top, and then discuss N1K through your comparison points.
3. It is over 100 pounds heavier than the N1K and about 150 pounds lighter than the Wing. So straight line performance will be about 75% between the two favouring the N1K. EG 0 to 100km/hr is about 3.3 seconds?
I think you should be able to do it in 3 flat. 2.7 if you get a Gen I.
4. What is the speedometer error? Assuming at least 6% has anyone tried a 190/55 series rear tire to have the speedometer read closer to actual speed? It is a heavy bike so I assume everyone is using the heavy weight spec on the tire of choice. What should I expect for milage on front and rear tires?
My experience is that it is around 3mph off at 70-80mph with Michelin PR4s, and Continental Road Attack 3s. It was spot on with Pirelli Angel GT A-spec in the Yamaha specified size. And of the three they have been my favorite.
6. Lean angle is favouring the sport side. What speed are you comfortable with doing a highway curve marked at 60 kph? I realize there is a lot of variance in posted speed curves, but there still is a 'norm'. I am looking for 100+ kph. Usually I just take the posted curve speed and double it for the comfort zone. This even worked for the Wing.
If a particular speed worked for the Wing, it will absolutely work for the FJR and RT. I think you'd scrape/drag a Wing before you could either an FJR or RT...
In short for riding style is it closer to sport or closer to touring? The ultimate bike for me would be the performance of the N1K with the comfort and weather protection of the Wing. From show room and checking forums it would seem to be 75% between the two in perfomce favouring the N1K and maybe 50% in comfort. I can live with that.
As long as you don't get a seat with "wings" like the standard Russell Day Long, you can slide back and forth all you want. Changing the windshield is common to change the bubble.
With the mileage you put on a bike, I'd think reliability would be high on your list. That is the biggest unfixable difference between and FJR and an RT. You can change seats, bar risers, move your pegs, and get different windshields for both, making each somewhat into the other. But you can't make the RT as reliable as the FJR.
I think I recently read that most recent years' Iron Butt Rallys have had more FJRs finish than start, because the ones that started all finish, and riders with others makes (notably BMWs) have mechanical issues and are often loaned FJRs so they can finish.