I’m not trying to equate EU membership with an FTA, New Judge. I understand that membership is considerably more involved than that. The point I’m trying to make is that there’s no way the UK can be absolutely, 100% sovereign over all of its affairs if it makes a clean break with the EU. In every possible scenario, we’re going to be taking some rules from elsewhere – whether it be from prospective trading partners, from the EU, or from the WTO. Domestic regulations are an important part of modern trade diplomacy regardless of whether or not they end up in the final text of FTAs. This usually takes the form of harmonisation or (if you’re dealing with the US or China), abolition.
This is why the USA has made it very clear that it expects us to drop our food safety regulations (for everything) if we want a trade deal. I haven’t read anything about what would China would expect – but you can be damn sure it would come with very similar strings. Even if we found those choices too unpalatable, and decided to forego trade agreements (which nobody except Mauritiana does) we will still need to take rules from the WTO – which *does* infringe to at least some extent on our autonomy (and is largely staffed by foreign bureaucrats).
You can either be completely sovereign, or you can be a global economy. Unless you’re a true superpower (which we aren’t), you can’t be both.
I get that this is all less intensive than what you see as EU interference in our economy at the moment, and that for you our sovereignty is the overriding reason for leaving. But if in practice we’re going through all this bother (or turmoil in the case of hard Brexit) to be ‘a bit more sovereign’, then frankly I don’t see the point.
Also, your assertion that “relatively few nations” are members of trade blocs is a bit misleading, because most nations are members of organisations that grant the same benefits as trade blocs (although by your standards above would probably count as a bit more intrusive). Look at this map of the world by major trade groups:
https://en.wikipedia.org/wiki/Trade_bloc#/media/File:Economic_integration_stages_(World).png
You’ll notice that the only absent areas are either huge global powers or seriously underdeveloped. You’ll also notice that plenty of trade blocs like ASEAN, MERCOSUR, and Eurasian Economic Union do provide for free movement of capital or people (in fact MERCOSUR in a lot of ways has even less regulated movement of people than the EU does, although it doesn’t have a court for settling disputes). CARICOM and CEMAC (which also provides for free movement of capital if not people) also practice harmonization of regulations, as do many others. I haven’t checked each one, but it’s my understanding that plenty of these groups also do prevent their members from striking bilateral trade deals.
This is the world that we’re really stepping into in a hard-Brexit scenario.