Why Attack Soldiers?

It looks like the lunatics decided to "defend" Northern Shomron rather than Gaza. That decision was probably a result of the IDF's ability to keep most of the infiltrators out of Gaza.

I've posted before about the motivation to passively resist. But what might be the motivation to use violence?

It would seem all four reasons would apply, although they would not necessarily apply to the same group of people who might resist for those reasons. Reasons two and three would apply only to people who are more intense in their religious devotion (at least according to the train of thought that views settlements are a key element of religious identity) or are just more upset and want to take out their anger on the soldiers; the soldiers are kicking them out of their home, but more than that, they are the representatives of the state that betrayed them. So some people might feel they are fair game.

Reason one would only seem a legitimate basis for violence to those who feel that we must show the world that Eretz Yisroel is so important that it's worth the costs of armed resistance: civil war, death, disunity, and a broken national morale. Reason four would make sense only to those who feel that passive resistance is not sufficient to deter future withdrawals, which rationally should be as high, or even higher, a percentage of settlers than the resisters. Interestingly, however, many more settlers resisted than have committed violent acts, and despite the hilltop youths extremism, the ratio will probably stay the same. It would seem that moral considerations have led most settlers to realize that deterring Sharon from evacuating parts of the West Bank is just not worth the cost.