Is the only difference between the Barracuda V and the Barracuda 7200.7 the fact that the 7200.7 does not have allow an external utility to change the acoustic/performance characterstics?

I think I heard that Seagate were forced to do this because of some copyright or other legal issue. Is this correct?

The second part of your post is correct.

I can't answer the first part but I'd guess that there's more difference than just the lack of AAM support. The cuda V has a SeaShield for instance, and the 7200.7 doesn't. There's probably more too.