I think the opposite. The EU needs to make leaving as painful as possible for Britain, to dissuade other member states from considering similar referenda. And, now that the British economy is crashing, Britain has nothing the EU needs. The EU can be as punitive as they want to be. They gain nothing from being nice to Britain, or making things go smoothly for them. By leaving, Britain threw away the only cards they held: Member Status. Now they are another Moldova... a country on the edge of the EU with little to offer, and everything to gain. But yes... I do believe the EU will go through an internal process house-cleaning, and take dramatic steps to increase their agility and responsiveness to member states' complaints.
In terms of having a say in trade agreements, the UK's trade with EU members is a much more significant bargaining chip than its member status. The UK hasn't stopped producing goods and services, nor has it suddenly ceased all trade with the EU. EU-UK trade is beneficial for both parties, and it will almost certainly continue in one form or another despite yesterday's vote. As for being punitive, undoubtedly there will be some petty politics, but from a pragmatic perspective, neither the UK nor the EU benefit from drawing out the negotiations. Investors don't like uncertainty, and there's going to be uncertainty until new deals are signed.
The EU gains nothing from letting Britain off easy, and has everything to lose. Making it easy for Britain to leave and maintain all their existing trade agreements with EU partner states simply emasculates the EU and everything it stands for and is trying to accomplish. The EU hasn't even existed for a generation yet. And the real benefits won't be felt for two more generations. You need people BORN in the EU - and their kids - before you have the cultural identity established, and treasured, by those who live within it. When separate states is an inconceivable state for those commuting to work every day. If the EU is going to live through this, they have no choice but to run Britain through the wringer, and make them jump over every possible hurdle they can conceive. Otherwise this amazing experiment dies before it even reaches puberty.
You may well be right. Ultimately it's hard to say how individual states will react. Juncker was fairly testy in calling it "not an amicable divorce", although Hollande was more positive and Merkel mainly urged caution as well as reportedly stating that relations with the UK would be "close and based on cooperation". Personally, I think that money talks, and the EU will want to continue to have access to UK markets and vice-versa, so future agreements will have to be somewhat beneficial to both sides (although I'm sure compromises will be made on both sides, as well). There is some danger of other states wanting to leave (thus threatening the integrity of the EU) but, as I mention in another reply, referendums take time to organize, and in some ways the UK was better positioned for an exit than a lot of other members. It's difficult to say how many countries will actually even put together referendums, much less leave, but I think it's a bit premature to claim that the EU is in serious jeopardy, even if the UK's exit is smooth/beneficial. Personally, I'm hopeful that future agreements between the UK and EU are drawn up with cool heads and based on sound economic principles, rather than being predicated on the idea of punishing the UK or on a fear of being 'emasculated'. Ultimately only time will tell, though.The EU gains nothing from letting Britain off easy, and has everything to lose. Making it easy for Britain to leave and maintain all their existing trade agreements with EU partner states simply emasculates the EU and everything it stands for and is trying to accomplish.
The EMU, for one. Those who have taken on the Euro would need to develop an entirely new currency if they chose to leave. And implementing a new currency from the ground up - design, minting, etc - is phenomenally expensive. That right there will keep the smaller countries around. I do miss the Dutch Guilders. Prettiest currency ever made. and in some ways the UK was better positioned for an exit than a lot of other members.
One of England biggest products is its banking services sector. Im sure other countries would be happy to take a piece of England baking pie and will maneuver to create uncertainty for English banks. As for trade it may be more difficult for England to negotiate for its own interest now that it has threatened to leave. Carve outs for English businesses and industries may be ignored because hey they are leaving anyway so why bother.