120mm, I have been thinking about this for awhile and I would tend to agree with you that the 72 virgins is not the real motive. I do think that many radical Islamic leaders would like the US to believe that thousands of bombers are out there waiting to attack on command for Propaganda reasons but I am not sure that is really happening.

So what if you went the other way? What if the bomber is also a victim being exploited by radical clerics,etc. In my LE career I ran into a fair number of suicidal types who are in such despair that they do not mind taking their own life or whoever happens to be around them when it happens!

How hard would it be to find someone in Iraq who lost one or several loved ones, does not have a job, does not have a home? How many would have had all of these happen to them? Probably a fair number. The Secret Service has done some fantastic research in this area and they have some documents at their website that are open source. They also have a LE restricted website that has their main manual for LE Threat Investigations which covers several of the questions you bring up.

If you can get access to it I highly recommend it and I am personally familiar with it. I have also done these types of investigations in the Domestic Violence/Stalking situations and there are allot of similarities.

I sparked enough interest with this that at a 2006 AUM (Auburn University Montgomery) seminar about my own experiences with it that US Army Intelligence showed up besides a bunch of Feds,State and local LE.

Here is the link to the Secret Service National Threat Assessment Center go to the down load section for open source material, any of the School Shooting Information is also applicable with some modification. A targeted attack is no different then an attack on a public official according to their theories which I believe very Strongly. One they don't believe in profiling. Two they do belive that attacks can be predicted with in certain peramiters.
I have had personal communications with some of the agents that were authors of these studies so it is some good stuff , so take a look if you have time.
http://www.secretservice.gov/ntac.shtml