Do Imperial Stormtroopers have honor?
They are organized in fighting teams. They are expected to show strength and courage, and to demonstrate mastery of weaponry and fighting tactics. Many are killed or wounded in action. As there is evidence of rank, Stormtroopers who demonstrate loyalty and bravery are surely rewarded or promoted. If there is anything human about them, Stormtroopers would probably mourn and eulogize their dead comrades, though admittedly I can recall no evidence of this.*
While soldiers of the Galactic Empire are viewed as evil enemies by members of the Rebel Alliance, and they are the “bad guys” in the Star Wars films, it seems likely that they would have the same sort of internal honor culture found in any military organization. They may be employed by an “evil” empire, but Stormtroopers would not be “evil” to each other.
Within the context of their organization, we can reasonably assume that Stormtroopers have honor.
It is only when we attempt to judge their actions or their mission from the Rebel perspective or according to some universal (or specific) idea of morality external to their organization that their “moral honor” comes into question.
“Well, whatever you do, however terrible, however hurtful, it all makes sense, doesn’t it, in your head. You never meet anybody that thinks they’re a bad person.”
— The Talented Mr. Ripley  (1999)
Stormtroopers are fictional characters, but contemplating their honor culture is a useful exercise. Most men are familiar with Stormtroopers, but have no profound emotional connection to them.
The idea of honor comes up frequently in discussions about what soldiers do around the world today.
A soldier’s honor can only be judged fairly within the context of his organization. If he is loyal and brave and respected by others within the context of that organization, he is honorable in that context. He may be your enemy, or he may fight for an organization which you consider to be immoral, or he may take actions on behalf of that organization that you consider to be immoral or contrary to your interests. This is an inaccurate and biased way of assessing his honor.
A fighting man, by definition, cannot be a friend to all mankind.
No man can, really.
A man who is a friend to everyone has no real friends.
Loyalty is preference; it requires discrimination.
* For the purposes of this essay, I’m sticking to what you can see in the Star Wars films. If you look up Stormtroopers on Wookieepedia , there are all kinds of storylines and specifics for advanced Star Wars nerds. I picked Stormtroopers here because almost everyone has seen the Star Wars movies, and can identify the men in white armor as soldiers of an “evil” empire.