/dll -u doesn't seem to spit out any error messages whatsoever.

I think it should have a few error messages:

/dll -u non_existant_dll.dll
* /dll: dll 'non_existant_dll.dll' is not loaded.

/dll -u dll_that_cant_be_unloaded.dll
* /dll: unable to unload 'dll_that_cant_be_unloaded.dll'

I don't know if the second ever occurs but if it does I'd like to see an error for it.

I think, although I'm perfectly willing to be corrected, that the -u switch, as you are showing, is similar to the way that $remtok works, in that if the item to be removed doesn't exist, it just doesn't do anything. Likewise with $addtok, and the item already does exist (as described in the help file for $addtok).

That's what I think also. I'd still like a message saying it wasn't loaded in the first place though.