We are where we are.
Cold hard facts are there will be two sides in these negotiations, UK and EU.
UK comes to an agreement with EU, each side then has a position.
UK then unilaterally decides 'no, changed our minds'.
Like I said, do we just tell the EU to accept that or do we involve them?
Please, try to answer that one!
That aspect makes no sense to me.
It could clarify those things now, before Article 50 is even triggered. Parliament (or the electorate) could be given the chance to consider that position, and see if it wanted to proceed.
The argument that the government does not want to reveal its hand is specious. If those things were clarified up front, the negotiations would proceed on that footing. But they won't do that, because of one of two reasons (I'm not sure which is correct): either they have no plan and all is chaos and confusion, or they don't want to tell Parliament and the people what it is they are intending to negotiate on, or what kind of Brexit is their desired outcome.
The government could state upfront to the EU that once a deal is offered, they will consult Parliament/the electorate before agreeing to take it or not. They could also make that clear up front, both to the EU and to the UK.
As to it being "deal or no deal" at the negotiating table, you portray it as if there will be a single meeting, with an ultimatum at the end of it. But let's say that's the case: in your scenario we'd have to take the deal no matter how bad it is, because otherwise we would upset the EU by refusing the deal they've offered us after all their hard work and effort. If so, they need not offer us any concessions, as we would be duty bound to accept regardless. May has made it clear she would rather take no deal than a bad deal (i.e. crash out on WTO terms), which clearly would also be a rejection of the EU's offer.
