Benn's Maastricht speech is very good indeed (I've read it before).
One of my first jobs out of university was negotiating single market legislation, which took me to meetings in Brussels on a regular basis. I won't go into details because I think it's still covered by the 30 year rule (just).
It has always left me scratching my head at the claims that the EU as it now is (it was the EC back then, the second E having been dropped as it moved from being just a trading body towards something else) was just a trading organisation. It was clear to anyone involved in those negotiations that what was being proposed was not just free trade within Europe, but higher trade barriers to the outside (not the crude issue of tarifs, but the subtler but more Draconian non-tarif barriers around health and safety, many of which were politically rather than scientifically driven - I used to attend these meetings with specialist scientists, as did the other member states).
The other thing was the extent to which it was driven from the top down by the Commission. I've sat in meetings where the scientific and trade experts from all the member states were unanimous that what was being proposed was crazy and couldn't work in practice, only to have the Commission chair overrule everyone.
The EU isn't an antidote to the nation state, it's just a bigger one, and one which is off shoring/outsourcing its own refugee crisis (camps on Lesbos/in Turkey, etc).
One of the things I've found interesting about the last 3 1/2 years is that Brexit has had the slightly paradoxical effect of making the EU much more open about federalism being the end game. (It's implicit in the Treaty of Rome, and is, I think, becoming more pressing with the instability of the Euro; if it's to continue, the Eurozone needs centralised control over fiscal as well as monetary policy). Ironically, I think it's Brexit that's brought this about, because they don't have to keep up the pretence that this is just a trading block to keep the Brits from getting too restive; either we'll leave (the overwhelmingly likely option), or have to return suitably chastened.
But make no mistake, it's going to be a very bumpy ride economically. The EU as a block is massively trade protectionist. The small corner of legislation I worked on sent New Zealand into a 15 year recession; talking to friends in other departments, that pattern was repeated round the world. We're about to be on the receiving end of finding ourselves as a third country.