"somewhat like the Continent being cut off due to fog in the Channel?"
Not really, just trapped with the regulations of the EU. Of course anything sold to the EU must meet such regulations but others manage that well enough, while the rest (majority) of business doesnt have to meet EU standards. We can make what we want to buy to the specifications we want.
"It is the EU that has plenty of trade and culture within its own borders"
Well said. This is a point I seriously agree with, it is a very good cartel to the protectionism of those within the cartel but not so much for those outside. Unless there is a trade deal that favours that particular trade.
"not to mention trade agreements with all parts of the globe"
That I must disagree with. They seem to be lacking trade agreements with various emerging markets which we should absolutely want to be taking advantage of such as China. And since China have expressed interest in a trade agreement we amusingly may get one before the EU! However the cartel does block out the poor by forcing high tariffs against countries that can compete, all in the interest of protecting jobs.
"Nothing has happened yet except for some post Article 50 chats that did not go well"
I do love this as a reasoning. Anything considered bad goes under brexit while anything considered good gets the 'we aint left yet' pass. As for chats that didnt go well, I think things are going reasonably well and as long as the gov recognises that no deal is still a very good deal for the UK we can be happy that no deal is the worst outcome the EU threatens us with. The worst deal we can get is to remain in the EU.
"I keep feeling we've heard the crunch of the iceberg against the hull but, so far, everything is fine, isn't it, because the decks haven't started to tilt."
I must admit I feel it too. The Euro currency should have been dissolved but instead a country was sacrificed. The utopia dream of equality destroyed when Germany unilaterally invited the middle east to move in. The idea of competent trade negotiation was tarnished when the EU gave up its sole reason to exist over the Canada trade deal and got held hostage by a tiny section of the population. Their kind faces twisted when they try to subvert elections. And of course the illusion of a friendly club washed away by demanding punishment of those who dare consider the option of leaving.
My main concern though is for over here in the UK where the idea of democracy, freedom and choice has been bought or coerced away by anti-democratic people who feel the result of the referendum should be ignored because x,y,z of poor excuses.