In my experience, I find that military personnel who have just reentered civilian life are excessively polite, especially former Marines.
Semper Fi Dan, very well said!
As far as a reintigration period, you have to remember that probably 75% of the military is composed of members in HQ or support roles (beans, bullets, band aids) not the infantry.
When I was discharged I was debriefed by the CO of my unit, because I have a security clearance and was always in possession of classified equipment (communications stuff). I was a wireman/radio operator that was attached to a grunt unit, meaning I did all the same training as them, I just carried the damn radio.
I never had any debrief on not going out and using the tactics you learned on civilian targets. But then again, I was honorably discharged, and in the Marine Corps eyes a decent human being. Maybe we should follow those who are discharged under other than honorable conditions a little more closely, especially if they were trained in some of the more lethal stuff.