The requests are obvious. Control;
Control over all law making
Control over all defence strategy
Control over sovereignty
Control over all home affairs and all foreign policy
Oddly it's what all countries have other than those tied into the Euro project.
Are there that many laws that will be changed now or deleted if we leave?
We seem to run a different military strategy to the EU in many cases. See Iraq and Afghanistan.
Sovereignty. Debatable what we can do with it on our own - even in our wars we rely on US or NATO support. We have to make compromises anyway e.g. comply with international law. we are in the United Nations and have to abide by their decisions.
We are not in Shengen, so there is no discussion there.
We have large amounts of control of Home Affairs anyway - it is usually human rights laws or employees rights ( e.g. working hours ) which upset certain peope. If we do any sort of deal with the EU, we will still have to comply with most things.
Is our foreign policy that good, that we must protect it at all costs?
A strong Europe pulling together - yes, it needs reforming - would be good enough for me. A cohesive foreign policy for the part of the world where we live is desirable, not something to break away from.
The empire has gone and we are far better working with NATO and Europe than trying to punch above our weight.