Exactly right, thanks for adding that. And the chassis has to be strong enough to handle the horsepower, the brakes strong enough to haul the bike down from higher top speeds. So all the components are heavier on a 1000.All of your points are entirely spot on. However, the massive thing I notice missing in your breakdown is the mention of rotating inertia. No matter what suspension setup you dial in, absolutely nothing invented to this point has been able to counteract the gyroscopic forces of big heavy 1000 parts slinging around almost as fast as smaller 600 parts. Mladin and Doyle in Sonoma measured trap speeds through 6 at infineon and compared vs Yates on the 600FX bike. What they found was the 600 was pulling 5-7mph fairly consistently on the superbike.
The reason this was launched was Honda's big push to turn 600FX bikes into "superbike," class under the guise of safety. The argument was made by everyone (read: not honda) was that the higher corner speeds were contributing to the lack of safety, not big displacement. But, at the end of the day, essentially unlimited 600 vs. unlimited superbike.. the 600's still run faster through the corner. It's not really curb weight, it isn't really setup, it's not budget. It's rotational inertia.
One interesting thing of mention is how much longer the BSB/SBK swingarm is than the factory arm. They're trying to have the best of both worlds, as LDS was speaking to. Trying to keep wheelbase short as possible, while leveraging against big HP.. flickability vs. driving hard off of corner exit.
If we apply latest tech to either displacement, the disparity will always remain.