"If the EU do not allow it, how do "we" get a vote for our leadership?"
We dont. We didnt vote for any EU president as far as I am aware, nor did the other member country populations. We vote our own governments however.
"I did not choose May, Cameron, Brown, Blair, Major, ..."
Did you vote? If you did you took a step far larger than you are allowed in the EU. Did you choose Junker or any of the others?
"Yes I massively want to neuter all politicians. I do not vote for them to do things I want. I vote for a hung parliament in the hope it will stop them doing a few of the things I do not want."
All politicians? So if you dont want politicians consolidating power and doing what they want then surely you want to localise power and make them electable? Or do you see the EU as so big and gummed up that it cant do much? Not saying thats a bad or wrong view, they cant seem to do anything important so the EU is in multiple crises, but they do manage to interfere on small matters they shouldnt be bothering with.
"Yes you do have a long post history. I read the first page of 60"
Now you see why someone wanting me to go through my history to provide a point they often dont care about is a waste of my time. If they care they can look.
"brexit will lead to any of: a stronger economy, more representative democracy, the economy again, lower prices when Brits buy and higher profits when Brits sell or that concentrating power in UK MPs will lead to anything constructive"
Most of that depends on the actions of the gov. They can do things that economically work or not. A good example is the last recession where the US and UK reacted to it and the EU didnt. The UK and US left the recession and carried on, the EU nearly landed in deflation and had a serious panic. Even now the EU is years behind the global recovery and the EZ (EU proper) looks to be failing again even after economies and countries were sacrificed to save the Euro.
The certainty is that concentrating power in the EU has not been a good thing nor constructive, instead demonstrably destructive to economies and moderate politics. On known information food should be cheaper on leaving due to the protectionism of the EU and by removing the EU above our government we will already gain in democratic terms (unless the gov does something antidemocratic. E.g. abandon what people have voted for).