Seems to me you're more concerned with "racial profiling" than with airline security. The angry Arab SS agent was apparently reading an anti-Christian book for Muslims. Seems to me this guy has an agenda, and so do you.
Right so let's kick him off the plane but let him keep his gun.
Sorry but this does not make me feel safe.
The Agent was reading a college level textbook on the history of the arab world. There is nothing anti-Christian about it although you maybe somewhat anti-Christian in your attitudes and behavior.
Maybe you are not aware that the agent in question was, up until a week or so before the flight, assigned to a FBI Counter-Terrorism Unit for three months where he receievd commendations for his work in helping to investigate and detain potential terrorists. It is quite conceivable to me that he was reading that book as background on Arabic history and culture so he could better understand the enemy. If you think your average Arab thinks like your average German you would be sadly mistaken. To be informed is to be prepared.