Is the Military Community Representative of the Civilian Community?

In my post about the murderous soldiers who are getting off easy, a commenter, Lone Ranger, wrote:

A military community is like any other community. Since they draw on the civilian community for their population, it couldn't be any other way. Forget all that hype about soldiers being "heroes," they are just like any other people. Some are great people and some are scum. Some are average and some are heroes. They just wear different clothing and have different jobs -- bring freedom to people whose freedoms have been lost.

While I understand what the commenter was trying to convey, I doubt that this is entirely a true statement since there is no mechanism for insuring that the people who join the military are representative of the civilian community. That service is voluntary means soldiers are largely self selected.

• Children of the well to do may be less likely to sign up than those with fewer economic and educational opportunities.
• Southerners make up a disproportionate segment of the military population.
• It is said, although I cannot say whether it is true, that the military is much more politically conservative than the civilian population.
• The military is skewed toward youth due to retirement requirements.
• The military is significantly more male than the civilian population.
• Christians will, of course, eschew military service as it is utterly incompatible with discipleship; therefore, the military will be largely devoid of moderating Christian influences. (The exception consists of those poor souls who were duped and recruited under the erroneous assumption that they would be "defending their country". )
• In addition to Christians, anyone else of any religion or other moral system having a scruple about homicide will be reluctant to volunteer for duty which could entail it. Accordingly, the military will necessarily be populated by people who believe that killing at the behest of government is permissible and appropriate.
• It follows that the military will be full of devoted statists and lacking in libertarians and anarchists. (Sadly, it is perhaps in this way that the military most closely resembles the population at large.)