>>2
I agree with most of your points. However, what fuels BNP's popularity is the increasing and alarming uptake in non-White immigration to Britain. The current government does not heed to the majority's concerns, and only listens and abides to the minority. The people then have nowhere to turn to until they discover BNP, and feel that BNP is the solution to their problems.
They remember a time when Britain was much less immigrated and integrated in their parents and grandparents times, and they generally feel that society was in better shape back then. So that also probably explains the popularity as well.