You are worring of a lot of stuff, which is not really necessary.
The newest version of the Addon Manager is obviously compatible with Cloud9 sceneries, provided of course you are using the current version of the sceneries.
And, of course, you can verify that your Cloud9 sceneries work, just by installing the Trial. And, who told you that, just by updating the Addon Manager on the same machine, will require a reactivation for Cloud9 sceneries ? As clearly explained, basically everywhere the Addon Manager is explained (including all the manuals and all the FAQ on this website), a reactivation is needed when you change a major hardware component, or when you reinstall Windows from scratch. It's surely not needed when the Addon Manager is updated.
There WAS a case, with Cloud9 products, that you needed to confirm the activation, though: the change of Cloud9 policy from 2 to 5 activations per order was the only reason why, in this specific case, just updating the Addon Manager, required an online check, in order to upgrade your machine with the new (better) Cloud9 activation policy. It was a one time-only thing, that will never happen again. But I think your current Addon Manager is already newer than that, because it happened in March 2008, when KORD was released.
Also, it's not true that, if you purchase on another machine, you use an activation that would be wasted just to get a .REG file to move on the machine you are really going to use. This might have been true for Cloud9 products, but our products have an additional option, not available for Cloud9, which is the purchase on the Web. You still will use the Addon Manager, just selec the "Buy on Web / PayPal" option instead of the "Buy" option.
This will launch a browser that will allow to buy products on a web page, but the scenery will NOT be activated on that machine automatically. You'll get a purchase receipt via email, with your Serial Number, and then you can use the "Register Serial" on the OTHER machine, to activate that one, of course, using the off-line activation method, since that machine doesn't have an internet connection. This will consume only 1 activation.