I have several problems with the OP.
I can't wait to see American Sniper. I am fascinated by the idea of exploring the emotional toll on a sniper, which must have complexity and components which are not part of the experience of soldiers who kill in other ways. Yes, snipers are far away physically from their targets, but the scope brings them in visually and therefore psychologically close as they pull the trigger. Also, they can't rely on the rationale that "he was going to kill me, so I had to kill him first" like in other battlefield scenarios, to ease the guilt of killing. I am also interested in how Eastwood examines what sort of person it takes to perform that particular duty and perform it well.
Unlike the OP, I happen to think any person who signs up voluntarily for the American military (I'm only going to speak for my military, since I'm American) for idealistic reasons and is willing to risk their lives for American ideals,
IS a hero. I do think that some who join do so for practical reasons or no better choice, and for those, I'd assign heroism based on their actions once they are soldiers.
This obviously depends on one's definition of hero, but it also depends on other things, like defining things as altruistic that others might define as self-aggrandizing.
I also think some who are left of center politically are angry about this film and are scapegoating Kyle in order to counteract the pro-military/pro-fighting terrorism response the film has received thus far.
Terrorism? He was in Iraq following 9-11.
It appears Kyle may have lied/embellished the truth about some stuff after his service. There can be a multitude of possible reasons for that, (according to D Magazine, he survived three gunshot wounds, two helicopter crashes, and six IED attacks during his service.)
Which may be bullshit as well. Maybe he was a jerk. That doesn't take away his heroism in the military.
You suggested your judging of his heroism was based on his enlistment, not actions. And that doesn't make him a psychopath. He did, however, care enough about his marriage and being a father, to leave the SEALs.
Unless he was lying about that too. And after his discharge, he worked hard to help soldiers suffering from PTSD.
Which did several things for his mythology, and allowed him to pursue his... hobbies. Those aren't signs of a psychopath. I also think Opty's charges of racism are misguided.
I'm going to agree with David French in his National Review article from Jan 16:
Responding to the American Sniper Backlash: Angry, Remorseless Warriors Are Still Heroes
http://www.nationalreview.com/corne...y-remorseless-warriors-are-still-heroes-david
And:
And: