This may sound silly, but as a result of being unable to use the normal activation via ISM (the manual license installation procedure worked fine, once I discovered it), I now have extra licenses/activations that I do not need. Just in order to avoid any future trouble, is there any procedure for "returning" the unneeded serials? If so, please let me know how to provide them.
There's no procedure for returning unused free student licenses, although it makes sense to avoid the confusion of having multiple serial numbers. Let me know which license(s) you don't want to use in a private message and I will retire them for you.