Have you heard of QTM? Quantity theory of Money?
Yes, I know about QTM and there had been big debates about it but now most economists agree on neutrality of money supply in long-run(i.e. direct effect on prices), while in the short-run monetary policy might be used as a policy tool. You can find the details here:
http://www.mpls.frb.org/research/qr/qr1931.pdf
Now, coming to the role of Central Bank. Its usually designed to keep in check the inflation and business cycles(booms and bursts) while currency stabilization is the last(unimportant) task. So, if I understand you correctly you mean to say- currency exchange rate stabilization as defending the currency.
Coming to your observation about Germany. A strong Deutsche Mark was eating up the economy(decreasing German Competitiveness) and so other nations would have caught up in the long run. Merging the economies together gave Germany a bigger market and helped in maintaining their competitiveness(the bigger euro did not appreciate as much as Deutsche Mark would have otherwise). Currently, Germany has the lowest unemployment rate(~3%) historically. Had they continued to run trade surplus, currency appreciation was inevitable, which would have led to reversal of trade balance.
Coming to the Chinese- again you made right observation and analysis. So, the point I made was that Chinese are suppressing(devaluing) their currency intentionally. How?? There is capital account other than the current account in national accountancy. So, dollars earned through selling goods are sent back to US to buy back Chinese Yuan through Capital account. i.e. the Chinese acquire stakes in American firms and are actually the biggest FDI investor in US. So, CCP is driving its power by devaluing its currency. So weak currency is a boon for export-oriented nations and that is what CCP does so well.
Although, relating this whole process to OWS protest does not make sense. The biggest problem with printing money is inflation but there are no such signs in US right now. As far as OWS supporters go, they are barking on the wrong tree. The growing income inequality and the reduction in middle class is definitely a concern but it cannot be related just to the conduct of monetary policy which is neutral in the long run. Given that the Fed has effectively kept inflation under control for all these years, there are other profound reasons for rise of inequality and not what you suggest. The rise of few Chinese elites might be related to concentration of power in few hands, but US is a different country and rising inequality there is something which is seeing some heated discussions in the economics fraternity.
So, effectively I do not see a different point of view. I almost agree with your description of the problem except agreeing to a correlation between OWS and currency devaluation and the role of central bank.