If we put forward proposals and they don't reply (or make a counter-proposal which is unacceptable to the UK), and the clock keeps running, we are going to end up with an unplanned exit. It is difficult to see how that will not be chaos. But there seems little consensus even within the government as to what the goals should be for negotiations, which is not surprising since there was a huge range of positions put forward for Brexit in the referendum campaign - from the 'Norway' model to WTO terms only. So far, reaction from EU states seems less than lukewarm to anything proposed by the UK. Time has been wasted with an election. It is difficult to see anything which looks like progress.
And when we are on the outside of the EU, Northern Ireland and (probably first) Gibraltar are going to come under enormous pressure. If Ulster has no fenced border with the Irish Republic then how will duties be levied? If they are not, will we levy duties on everything coming to Holyhead, Fishguard or Liverpool from the island of Ireland?
Sorry Pete, but I remain firmly in the better the devil you know camp. Causes for optimisim about the consequences of leaving the EU escape me. It is not that I am not looking for them. They just are not there to see.