A pretty minor clip, but given its context, I'd certainly think that ought to command a bit of a premium...?
Clips are quite uncommon in mint sets as are most errors and varieties. When clips are seen they are very small like this usually.
Yes, it looks like it. That is pretty cool. I also found a minor clip on a Franklin half from a US Mint Set.
Nice little error! I'd assume the premium is greater with the coin still being in its original cellophane, along with being uncut (the cello, not the coin - the coin is obviously cut... haaa! ). So whatever you do, leave it in the packaging. and congrats on the find.
It is neat and adds a small premium. Emphasis on the word small. You want tough though try finding one in a proof set.