Here are my thoughts:

1) I'd agree that we can and do use the three words mentioned synonymously. That said, I think they can and sometimes do carry different connotations. I hear a lot about the French Revolution, not the French Insurgency. Maybe the magnitude of the changes wrought cause it to carry a different name? Another thoughts: is using "Phases" to delineate stages of an insurgency overly dependent on Mao's theorizing? After all, isn't it the ostensible spontaneity or rapidity of revolutions that makes distinguishable from other phenomena? ("And all of a sudden, one day in 17XX, everything changed.") I'm probably picking nits here, or not disagreeing with you at all, but just some thoughts.

2) Sex IS interesting. No, seriously, my sense is some insurgencies integrate women into their operations far more than other insurgencies. At the other end of the spectrum, my understanding is there's a female warlord leader somewhere in the contested part of Burma/Myanmar. Presumably, everything being equal, one would want as many boots on the ground, so to speak, female or male. So it's interesting the power of culture (and obviously not one limited to small wars or insurgencies): to gain permission to fight, to decide to let women fight, and the ways they do it ("Well, you'll fight, by putting these rivets on these planes.").

3) Grievance, in my opinion, could be utility-maximizing or emotion, although I think in common terms we think of a grievance as something purely emotional rather than something purely utility-maximizing. I don't see why it couldn't run down the whole spectrum - "I do it partly because I think there will be wealth redistribution when we burn down X's farm because he's on A's side, and also, by the way, I don't like X, and if you asked me to tell you what proportion of my actions are driven by calculations of utility and what proportion are driven by calculations of emotion, I wouldn't be able to tell you; I see a window of opportunity to do something I want to do, for reasons I'm not quite sure of, and I act." Obviously long-standing grievances might differ greatly from my lame example, but nonetheless, why a grievance couldn't be both emotion- and utility-based in any proportion eludes me.

I think even the word "grievance" might be misleading, because it carries connotations of emotion: rationale might be better. That's Stathis Kalyvas's take on FM 3-24, based on my reading of the Perspectives of Politics article by him I read, and how it intersects with the greed versus grievance literature on civil wars; basically, FM 3-24 assumes insurgents operate because of grievances, not greed. Ergo, fix the host nation, one eliminates the rationale for the insurgency, and one eliminates the insurgency. But if insurgents aren't motivated by grievance, but greed (which is an emotion, now that I think about it), then "the solution" changes.

4) Regarding why a man blows himself up, I'd take a look at an article by Ehud Sprinzak in Foreign Policy from about 5-10 years ago (wish that I could recall more closely its date). You can probably pick up the big RAND works on terrorism (try Darcy ME Noricks's articles for citations, although I'm not guaranteeing it's there). Basically, people become socialized to kill himself or herself, but you can't make someone kill himself or herself (ie, upset enough to kill himself or herself.) You can identify would-be suicide bombers like the Columbine kids and nurture them along, but that's about the best you can do. That's what I recall from the article, though - don't hold me to it.

5) "Most serial killers and sociopaths are men" I think most would-be and actual presidential assassins are or have been white men of small stature, too.

Regards,
OC