Jim, right from the start they would immediately lose a net contributor to the EU budget, we are helping to pay the membership fee of many .
If we are out then these billions of euros worth of slack will need to be taken up.........I doubt there are any countries that will happily just pick up the tab.
You may not think we matter to the EU, but we really really really matter to Ireland, the vast majority of that small country's trade is with the UK and the US.
If the EU wanted to impose tariffs on trade with the UK they would ruin the fragile recovering Irish economy, which just happens to be in the euro, the currency they have to do everything in their power to protect.
These current friends of ours may want to be vindictive to the UK in the face of a democratic decision by the UK electorate that they didn't like, however there would be wider consequences.........the inners may not like to recognise it, but there it us.
Relax.
As an inner I am VERY concerned at the prospect of reintroducing boarder controls in Ireland.