There's a possibility the OP is leaving something out, but to me it sounds like she just doesn't get him in a very fundamental way; I mean, there are A LOT OF PEOPLE who are all like "yeah stupid America with their guns, military and religion." I mean is this really so shocking that someone thinks with this kind of political polarity in the United States? I know a guy with a PhD in philosophy who makes comments like this, and he went to fucking Vanderbilt, and he is not psychotic, last time I checked.
This stuff is all over the news. Has the OP not turned on a television or perused a political web site lately?
Also, making off-hand comments that someone who is apparently ANTI-GUN would shoot up a school is actually pretty nasty, I don't like this sort of cavalier attitude toward anyone who is a little eccentric or paranoid, like anyone with even a mild psychiatric condition is the next school shooter.
Lots of people also use their facebook as a political platform. I do. My ESFJ sister does.
NOW...what I think is disturbing is that he seems lonely, if he's seeking attention and not getting it and feels rejected by his peers, and then is posting the same rant over and over again.
That to me seems more like he could commit suicide than hurt someone else.
I agree that he is overly agitated, he really needs to stop surrounding himself with so much negativity, and he certainly could benefit from counseling.
But unless there are some really important details I'm missing, I think it's kind of disingenuous and/or cruel and/or ignorant, to jump the gun and say "omg this guy makes no sense and is psychotic."