I've been through a similar situation, resident here but working across Europe. Providing that your UK pension is transferred to a scheme recognised by the UK authorities (HMRC) there is no tax charge unless you have funds or benefits that exceed the lifetime limits there.
Once you have achieved six years non-residency all UK rules fall away and you can use your funds or withdrawal them without UK taxes. I'm almost near my six years and my advisers were brilliant - hence this note - as you do not need to move this money to a Swiss arrangement or a new employer's one. I've got an approved fund in another country where I can access my UK funds (90% as cash) as soon as I reach full non-UK residency.
The company are [moderated, suspect advertising/spam] - but I probably shouldn't give their details away without asking. The key fact missed all the other advisers I spoke to, this that you can move UK funds anywhere in the world, its just a question of finding the right one to suit you.
Wow, didn't expect to be talking pensions on my first post, but I reckon the UK revenue will crack down on this.
Anyone, know where I can locate an expert on property in Bulgaria?