Checking to see that the rear sprocket has been replaced is easy if you have ever seen the first edition. There is a marked difference between the first and the second. If there is someone that could provide a picture of the new one that would put that issue to bed. It has been replaced or it has not, simple.
The issue with the new regulator and the associated heat shield is a little more complicated
due to where the thing is located under the battery behind the lower left fairing. Once again it either was or was not and once you take the left side fairing off it is easy to tell by the metal shield placed between the regulator mounting and the front cylinder header.
I just bought a 2008 and the dealer told me the recalls had been performed and when I took the body work off it was indeed done. I could see the difference between the 2007 rear sprocket first edition and the second at a glance.
If I was home I would be glad to post the pictures but I am not so I can't, sorry.
Don't think too much about it. The rear sprocket is indeed a safety issue and is the easy one. Buy the bike you want and ride the hell out of it.
I found this picture of the left rear with the first gen. sprocket. You can see in the picture there is not much material between the cush drive, round attachments, and the sprocket/hub proper. The second generation is much beefier and very much noticably more material in the before mentioned areas.