There is not a *single* identifiable female or non-white imperial in any of the three OT films.

Meanwhile, women and non-whites, not to mention a variety of non-humans, *do* feature in the Rebel Alliance's command structure (Mon Mothma, Leia) and fighting forces (Toryn Farr in the Hoth Echo Base control room, plus a handful of other females...

http://fangirlblog.com/2015/06/the-evolution-of-women-in-the-star-wars-universe-episode-v-the-empire-strikes-back/

...and General Calrissian, plus a couple of black and Asian pilots in the Endor space battle; and a female commando in RotJ, at least in promotional material... - http://starwars.wikia.com/wiki/Dansra_Beezer)

Surely this was not a coincidence? The Empire's visible exclusion of any but white male humans was surely intended to lead viewers to relate it to the misogyny and racism that was at the very heart of Nazi Germany?

The EU's efforts to insert females and ethnic minorities into the Empire has therefore surely been misguided, not least in that it makes the Empire less irrational and unpalatable.

So, no female Imperial villains for me, thanks.

Part of it may have been intentional the other part was probably mostly just having British extras filling out the Imperial officership roles, standard US movie standards of making the British evil. Though I'll go along with the Empire definitely being prejudiced against aliens I think so long as they were human the Empire would take them, regardless of gender and race. Besides the Empire needed tons of recruits once it first started up to replace the clones, and since the Empire tended to have the recruits, and later officers and troopers, to compete with each other they would let anyone ruthless, effective, and loyal enough to have a position of power.

And you have to remember the (Palpatine's) Empire lasted only 25-26 years so a lot of the people in the higher positions of power were people who served during the Clone Wars, Yularen, Tarken, etc... So anyone who had enlisted during the GCW would have only spent a few years in service to the Empire, which didn't really allow for too much progression in the ranks aside from say Vader killing his officers, or having your higher officer killed in a battle.

...the Empire needed tons of recruits ... to replace the clones, and since the Empire tended to have the recruits, and later officers and troopers, compete with each other they would let anyone ruthless, effective, and loyal enough have a position of power.

This is not what happened in Hitler's Germany, the regime on which the Empire is visibly based. Never underestimate the tendency of ideologues to cut off their noses to spite their faces.

...the Empire needed tons of recruits ... to replace the clones, and since the Empire tended to have the recruits, and later officers and troopers, compete with each other they would let anyone ruthless, effective, and loyal enough have a position of power.

This is not what happened in Hitler's Germany, the regime on which the Empire is visibly based. Never underestimate the tendency of ideologues to cut off their noses to spite their faces.

True, but we do see this somewhat in the new canon and in the old EU with examples like Daala and Thrawn.