http://www.expatica.com/de/visas-and-permits/A-guide-to-German-citizenship-and-permanent-visas_108795.html
Is it a matter of
fact or more strong, unsubstantiated opinion? You
need the full German citizenship for the related EU citizenship rights and privileges. To get that, and a right to reside permanently elsewhere in the EU, you need to be an EC resident
at the very least; this is not as straightforward as some people think, and may take the best part of a decade on average.
Here's a list of requirements for the EC residency in Germany.
So, after you've spent five to eight years in the country, have acquired a livelihood and the requisite language skills, and are settled there -- why move to 'ol blighty?
Legal refugees have no automatic right to free movement or other benefits of a European citizenship. They can only reside in the country where they were granted asylum. Full stop.
There's a further set of conditions on free movement also: if you want to remain for more than 3 months in another member state, you
need to be able to demonstrate you can support yourself and have health insurance coverage. A “habitual residence test” is a common way to establish that, see Belgium for example. We have the power to use it, but to my knowledge never have. Whose fault is that, the EU again? It's in the treaties, Theresa May can ram a bill through parliament now, if she wanted to. But instead we point fingers, and we are planning cuts for the relevant departments instead, in or out. Comedy!