Note: I have very little exposure to the crypto ecosystem.

I either don't understand the specifics of the keying or it doesn't make sense.

There's some kind of private key. Makes sense. But there appears to be some kind of second key. At some point the note will "expire" and only the person who owns the second key can redeem the Bitcoin?

If I understand right, either the person who physically holds the note can update the key (in which case what purpose does it serve) or the key needs to be transferred along with physical possession of the note (in which case what purpose does the product serve).

Also what does it mean for the note to be "cut"? Like with scissors?

Is this product just intended for hardcore crypto folks or is it intended for regular people too?