Roughly speaking, the Bill is generally fair, in that it introduces licencing for professional dealers selling to private individuals, but also allows ministers to add specific conditions to licences. Then the policy memo goes on to explain how they're going to use this additional bit to impose a ban, with certain exclusions. Oh, and they intend to make it the seller's responsibility to ensure that the purchaser is eligible for one of the exclusions.
The policy memo also says this is all to cut crime. I don't see how.