Your previous post pointed out all the problems the EU has brought to the UK. You can't have it two ways unless you think stability, rising living standards, improved healthcare, only apply to other countries.
The peace you claim is due to the EU is bullshit.
The EU is only 25 years old, there was no political unity before then, peace is down to USSR and Putin being on our doorstep, disarming Germany and France, Nato, US and the Nuclear bombs.
As for workplace entitlements etc. The migration of millions of low skilled and non skilled EU workers has meant a deterioration in wages and an increase in part time and zero hours contracts. An excess of unemployed has made employers the top dogs in negotiations and an increase in people relying on welfare. Poland blocked Cameron's plan to introduce a minimum period migrants had to be in work before they become eligible for benefits.
The EU is on course to rule from the centre. Something that few Common Market countries voted for, Eire, France and Denmark voted against it, the UK would have voted against it if Blair had held a referendum as he promised. He didn't when he know he would lose. I'm all for the Common Market something that most of the prosperity most claim is a result of the EU. It isn't. All the other pluses are things individual countries could achieve without rule from the centre.
Lastly with Thatcher and the North. The only businesses Thatcher could close is those who were reliant on tax payers money to stave off bankruptcy. No business man closes or doesn't open a business because a PM closes a few.
Whether the South East should fund loss making industries in the North is a question you have to answer before blaming Thatcher. Closing those businesses created a large workforce, yet businesses do not go there and not because of a railway getting there 1 hour sooner. Most freight is moved by road these days. Check trucks on the motorways and count the European trucks to see how getting to Manchester in an hour less will effect business.
Company formation agents in Dublin, Amsterdam, Cyprus, Luxembourg, etc. Will be single offices and that won't effect their manufacturing plants. Companies that risk moving their entire operation to Europe because of Brexit are gambling that the UK and Britain will never do a trade deal. That won't happen.
The UK will have the entire world to trade with and on their terms. There is the problem. If they allow open door trade deals to the Third World they risk losing more manufacturing, R&D, Science, Technology and eventually everything the UK has to places where workers are on 20% to 10% of a British wage. Another factor of where businesses go to do business.