And you insist on doing math that's demonstrably wrong.
The person who runs that site does this for a living, and is a consultant to the suborbital (and orbital) space industry.
You propose a not-yet-built-still-on-the-drawing-board concept vehicle to do this.
No, the vehicles are already designed, and being built as we speak, in Mojave, California (by Burt Rutan's company) and Oklahoma, among other places.
The math was done at that web site. Didn't you read it? With a fleet of a couple dozen vehicles (about the size of an executive jet), four flights per day per vehicle (it's just up and down--a flight lasts only an hour or so), a hundred flights a day is a conservative number.
I really don't understand what your problem is here. This is straightforward aerospace engineering, with mature technologies.
Except for the "excutive jet sized" thing, that's what I come up with too. I used the figures for a 747 as a proxy and came up with between 60 and 170 flights a day being sufficient to hoist 5,000,000 tons a year. It's probably closer to the lower number because the higher one assumes the plane would be fully loaded with fuel which isn't necessary just to fly for a couple of hours to discharge the cargo.
BTW, I much prefer a "space shield" approach since it can also be used to raise the amount of heat deposited and combat the coming ice age. Ultimately we might have a fine enough understanding to control climates quite precisely. Maybe even eventually some control of severe weather.
This is certainly not straightforward. It is a postulate and nothing more. Since this SOV is merely a concept in some engineer's mind and has yet to be built, it could not be scientifically proven, it is not even a theory.
You site no empirical evidence in any argument you present. Rather, you defer to: "This actual guy says this and that" but go no further toward justifying your remarks.
Your reasoning is flawed in that you site a company that pioneered in ultralite aircraft- hardly an attribute for commercial cargo hauling sulphur into the stratosphere in a vehichle that has not yet been built tested.
As for mature technology, that's the domain of Irrefutable Scientific Fact
You happen to ignore the fact that the re-launch time for Burt Rutan’s vehicle was measured in weeks. The Payload was 1 human being. Need more math.