This is definitely not a showstopper for N9. It is a showstopper for your use of N9.

Could you please change the topic to be less provocative and more to the point? With sensational titles you don't reach your goal.

There is a thread for MfE on N9/50: http://talk.maemo.org/showthread.php?t=78480 which you can use to bring your issue directly to the MfE team.

Filesystem encryption and remote management are supported by N9 and if these capabilities are enforced on Exchange server side, MfE on N9 will obey them.