You can already create offline/hardware/paper wallets for NuBits and NuShares!
Using NuBippy.
You can safely store NuBits or NuShares offline. You can thank @woolly_sammoth for this bit of awesomesauce.
I’m not sure about the cold minting. @sigmike is on the Peercoin and Nu team, so I imagine if there’s some benefits provided for Peercoin it will be ported back over to Nu (and vice versa)