Cavalry user here, still taking questions.
1. The overwhelming majority treat it as just a job. Remember, the vast majority of military jobs are non-combat administrative or trade type jobs. Mechanics, S1 admin guys, cooks, what have you. For them its a simple 6am-6pm job that is much like the civilian life except for wearing a uniform. My experience deals with combat arms, which is a significantly different culture.
2. Dude, before we patrolled my section sergeant would consistently and nonchalantly give us the op brief before saying "now come on boys, do your jobs for Haliburton". We all knew to some extent what was going on (although being 19-20 years old when I deployed didn't help my world view, coming from an impoverished background not knowing shit). You also have to remember, unlike that dipshit above who doesn't seem to understand what the real world is we didn't go around pushing around Iraqis and rifle-butting little kids into the dirt. We handed out soccer balls, built a school, provided security for infrastructure projects, gave out medical care to the old and children, and generally spent a year being the tough guys for people whose own protectors (their police, their army) were all too happy to take a bribe or desert their people when they got the least bit hungry or tired. So no, we never sat around thinking "this is wrong". We weren't Waffen SS liquefying villages, and we never did anything the least bit morally questionable. But we knew the overall mission was bullshit.
3. We didn't feel any particular way about them. However, when encountered by Berkeley types like the aforementioned shit sucking faggot above we just laughed it off because none of them ever knew or considered how any of us got to being in the military or what we actually did. All of those people who yell "imperialist war machine" or "babykillers" really just show their own lack of knowledge and critical thought when they make blanket statements like that. You wanna get on people who kill civilians? Go harass the drone operators and pilots who drop errant air strikes on small villages. But we, the grunts on the ground (and I say this confidently) were strictly taught to avoid civilian areas and even disengage if there were civilians nearby (even though my element was never in combat, we trained tirelessly for these types of situations and how not to harm civilians). So to sum up, when confronted by people like the above who call us murderers and what not, we just walk on. Anyone who so quickly wants to throw out judgement themselves should consider their own sins.
4. Personally, you can read my thoughts on the article I wrote on bunkermag (Manufacture of an American socialist). It can detail my thoughts on the local populace much better than a small post here. But basically, we knew that they were just people like the family and friends we left at home. It was just a shitty situation for them, and we never really forgot that. Those kids, those smiling faces waving at us as we drove by made me just so glad I was able to do something positive for them because god knows their own government wasn't going to. But yeah, simply put we didn't view them any differently than we would view any other human beings. By the way, we weren't "invading" them.
5. We had an SF ODA on our COP (Combat Outpost), and they mostly stayed within their own compound. But they did offer and give us some training, and it was amazing and good training.
6. I'm so glad you asked this, because not a single one of my platoon was one of these types. While at the end of the day you'll get a lot of loud mouth POGS (persons other than grunts) who post all that pic related shit on facebook, when the rubber meets the road everyone knows we are just hot, sweaty and sucking because we were sent out there by politicians. No one is more critical of command and country than grunts in a hole, and I say that with confidence. Like the words of my section sergeant, mostly everyone had an idea of the bullshit that was keeping people there and why we were sent. It wasn't freedom, and it wasn't "sacrificing".
Always here, always taking more questions.