The not talking about what is important is not key at all. The EU members know that 12% of our tax take is from financial services, so they know that passporting is important to us. It is not as is the details of the UK economy are classified. The EU know what we rationally need. The silence is not poker tactics, its is sheer bloody ineptitude. The Government do not have a fucking clue what to do, and are prevaricating hoping that something turns up.
The problem is its all important to us, immigration control is as well for political reasons.
Its all important to the EU as well for political reasons in many areas (freedom of movement) but also for single market access given the hefty trade deficit we run with the EU, I'm not one of the headcases claiming we have the EU over a barrel, but we do have some leverage, albeit far less than they do.
The minute you say publicly what you need to achieve you are putting a massive political price for the government on not achieving that goal, and that can certainly be used in negotiations against you.
Neither side in this negotiation is offering anything at present, nor would I expect them to until Article 50 is triggered.
I fully agree that the government probably hasn't set out its goals internally yet, and the whole thing is a bit of a mess, but even if they had got everything organised I doubt you would see much difference in what is said externally.
It might make sod all difference in the end anyway, the EU may decide they aren't particularly interested in negotiating and its either scenario 1 - EU membership in all but name or Scenario 2 - Piss off and make do on WTO rules.
The UK will obviously hope that they can force some concessions and get something in the middle, time will tell if that is likely or not