I agree with what you tow have said: a little extra space on the harddrive does not hurt at all, and eliminating a little space will not help the problem. BUT since you both agreed with that, I am not sure what this would accomplish:

"Maybe unused names could be removed upon request? Deleting all names that haven't been used for a few months might be a good idea too, but it would be nice to send them a courtesy email first."

HOw would this reduce bandwith at all?