I know a lady who feeds popcorn as a treat but remove the husk & the kornal (sp?).
I also wouldn't give it salted simply because a friend used to have a flying squirrel...said he was late for work one day and tossed it a handful of salted peanuts only to return home to find it dead.
I'm sure a bit of salt won't hurt but if it were me and can be avoided I would do so.
Mala chowed down on the fluffy part of a piece of carmel corn the other night...she was in heaven! (Needless to say I was picking tiny pieces of carmel corn out of Zoey hind quarter fur not long after.)