Going out will change nothing (regarding immigration)
When Turkey have paid the requisite 28 backhanders it certainly will.
I don't buy that.
Much of the immigration in the UK from the EU is driven by economic difficulties and lack of jobs in other countries in the EU. Remember Auf Wiedersehen Pet ? Oz and his mates were doing just that when there was a lack of jobs in the UK, and like them, many of these people will return to their own countries when the economic cycle upturns.
The argument that 70 million Turks want to come and live in the UK is shameless scare-mongering of the worst sort. Turkey has quite a strong economy, with growth rates of around 4% and manageable levels of unemployment.
The proposals for Turkey (which are a quid pro quo for the fact that Turkey is bearing the brunt of the refugee crisis from Syria and Iraq) is that Turkish nationals should be able to visit Europe as tourists without having to get a visa. They would not have the right to work, nor the right of abode.