Caporegime
Why would the EU and its member states want to allow a Britain outside of the EU export goods to it cheaper than the member states can supply itself.
Take steel for example, the EU is being heavily damaged by cheap Chinese imports, do you think they would allow cheap UK imports?
It's free trade OldCoals old boy, they allow us to export to them tariff free and we'd allow them to import to us tariff free - win-win.
On your point about cheap steel imports from China, I feel the need to point out that they are allowing this cheap steel in at the moment, and not all of the EU is suffering as a result - German car manufacturers in particular will be overjoyed at the collapse in steel prices...