As the British authorities tend to be rather conservative in my experience, I suppose they would be willing to permit a name change only in similarly extreme cases as the German authorities.
I haven't really read the thread so can't really comment on the OP's situation, but skim-reading some of it, I spotted this.
Historically, the laws around this used to be incredibly lax in the UK. The UK has always had a very different attitude to this than the Continent (the same fiercely individualistic streak is the reason we don't have mandatory ID cards here). Technically you used to be able to use whatever names you wanted as long as your intent was not to defraud. You could disappear and start again with almost no effort. The name the government knew you as could bear little resemblance to whatever name you used at work, or for your bank account, or whatever.
This changed massively about 10 or so years ago, when strict international money laundering regulations were brought in. Now, you have to use your real name and prove it with official (photo-)documentation
Of course, even under the old system if you wanted to change your legal name, you did - and still do - need to inform the authorities and change it by deed poll. But this was - and is - a very straightforward process. You fill in a form, pay about £30, and that's it, job done. You can change it to almost anything you want (no numbers/symbols, etc).