The purpose was to clarify that the obstacles to constructing modern nuclear weapons is not accurately characterized as "99%" fuel-related. Even if a group were to obtain a stockpile of ready HEU and plutonium-239, there is knowledge they simply will not have because they did not spend a trillion USD testing different bomb configurations last century. The difference in yield is two orders of magnitude.
True for fission bombs. Less true for fusion bombs. The principal makeup and manufacturing of fusion device parts like tampers are still unknown to the public. Having a supply of HEU does not tell you how to assemble a functional triple stage device or how to utilize tritium, an isotope that measurably decreases in purity by the day.
Yes, they do. Advertising works. "Free with ads" isn't really free because on average you'll end up spending more money than you would otherwise. You're also paying more than if it was a subscription because the producer has to create both the product and also advertise it.
Large corporations are not your friend. They are the enemy; they vary only in type and depth of diabolicalness.