I don't think the keys will do anything unless the realism settings are such that they need to be active. That is, for example, prop pitch only shows up if you have CEM on, and the radiator commands only operate if you have the temperature/overheat settings on as well.
I couldn't figure out why my radiator settings did not seem to be doing anything after I had mapped them to my joystick .. and then I remembered to actually turn on the full overheat realism settings and the radiator buttons then worked.
I still haven't figured out how WEP works though but I am sure that is just me missing something again.