What sort of attributes or "character" would you assign to the major and minor keys?

E Major - strong and commanding
Em - almost boardering on evil

D Major - Strong, yet compassionate
Dm - Bittersweet sadness

A Major; Bb Major - Fun and party atmosphere
Am - loss

I could go on with the other keys, but it is subjective anyway.

You get the idea.

aggressive and passive...

dominant and subordinate

Really simple (and pretty universal):
Major-happy
Minor-sad
diminished-depressed
augmented-confused

Major ---- Grandiose... with pomp!

Minor ---- Sad... doleful.