I find it hilarious that the UK Government are wasting so much effort in trying to decide what Brexit will actually look like - As though it was somehow in their power to have any effect on it.
Their actual choices are: Leave with nothing; or Stay.
The idea that they can decide to leave, but keep some elements of EU membership, is fucking insane - Why would the EU let them do that?
They are like a child in a sweetshop with no pocket money, trying to decide which goodies they want, and which they don't - Whatever their final decision, they are going to go home empty handed.
Meanwhile they have pissed away two years without establishing ANY of the institutions that they will need to operate as a nation once they leave; And they now have nine months to set up regulatory and licensing authorities for everything.
To take just one example, the European Aviation Safety Agency certifies and regulates most aspects of commercial and private aviation in the UK today; Without either expanding the rump Civil Aviation Authority to take on this role, or establishing a new regulatory and certification body, the ICAO will not be able to certify the safety of air traffic in the three Flight Information Regions currently managed from the UK, and all international operations (and perhaps most domestic operations) in those regions would be unlicensed, uninsured, and as a result unacceptable to most carriers, from Brexit Day until a new body is in place and able to meet its obligations.
Flights from the Americas to Europe can simply divert north or south of this un-licensed region; The impact on the EU and the North American carriers will be noticeable, but manageable. But the impact on the UK could be disastrous. All international flights could be grounded. I cannot see a US carrier deciding to risk flying in an FIR not certified by ICAO - Their liability in the event of even a minor issue would be astronomical. Airbus are already planning for significant disruption to their manufacturing supply chain due to the unavailability of certified parts from UK suppliers after Brexit, and are seriously considering relocating their UK operations to elsewhere in Europe; And the UK government's response is to say that they are being foolish and that there is nothing to worry about.
This is not trivial; The skilled staff needed for a UK Aviation Safety Agency will take at least many months, probably years, to recruit. The UK government has nine months. And they are showing no signs whatsoever of starting the task yet. Instead they are saying that it will all just work out fine. Which is about as believable as the idea that leaving the EU will add £350m a week to the budget of the NHS.
And that's just ONE of the forty or so EU agencies that will disappear from the UK on Brexit Day, and which the UK Government has yet to do jack-shit to replace. Perhaps some of them are not necessary. But it's undeniable that some play a crucial role in the operation of the UK as a viable modern developed nation. And the UK government's procedure (in full) for ensuring a smooth transition is 'cross our fingers and close our eyes'.
What a clusterfuck.