You can't avoid losses because you can't let goods cross borders without oversight.

The EU has vital interests in controlling the consumer goods available in its market. If we don't have a say in, for example, how they control their food production, we can't just take their word on it.

If you now think, let's just assume the British government does its job correctly in that regard, and we'll be fine, you're wrong. Companies often know which of their products are going to end up in exports, so they know where they don't need to follow the rules.

EU as a whole perhaps. But not individual countries. For individual countries (e.g. Netherlands) political games will just increase the amount of people wanting to leave.

But why risk losses at all if you can avoid it?

Because there is the other risk of losing more member states when they see that there aren't serious consequences to leaving.

The act of leaving will already produce big consequences when the EU subsidies go away. Even with free trade the UK will be worse off.

Overall we did give more. Then receive in subsidises.

Source? Also poorer areas of the country(like Wales, which inexplicably voted to leave) received majority of their help from EU,not British government - and now can they expect the British government will match those contributions? How and with which money?

It's widely known we're a net contributor to the EU, it's not disputed at all. Money doesn't magically appear in the EU coffers, as the UK is one of the strongest economies in the EU, of course it's a net contributor.

The exact figure is disputed, leave were saying £450 million per week, remain were saying it's £150million per week.

https://fullfact.org/europe/our-eu-membership-fee-55-million...

You gave more*

*not including cheaper labor into account.

As others mentioned in the thread, to curb nationalistic anti-EU movements from the other countries.

To avoid larger losses later on. Tarrif prevent relocation if industry to cheaper working environments. Why would the EU want cheaper business in the UK ti compete with an advantage?

But the EU can't avoid losses. That's the point.

But it can avoid as much as possible