I wonder about some of the things you wrote. Not as a matter of contesting them, but in terms of thinking through them. This with the only sure knowledge being that it is impossible to predict what will occur in that part of the world EXCEPT: that it is like a pinball machine, a tilted table, where all roads ultimately lead to the ball falling thru the flippers, which in this (and all other) cases means an Islamist government.
It’s indeed the Egyptian Army on the border, AFAIK. It seems to me that the best way for the nascent (not really) MB regime in Egypt to demonstrate its power is to stage a war with Israel. This would be entirely typical for moron despots. On the surface, the force involved would be the Egyptian army but it also seems like a strong possibility that “genuine” Egyptians would rather not go to war. Thus, as you posit, perhaps the force that would go to war would be a hollowed out army, with Al Queda and/or Hezbolleh-figureheads in command. Such a force is not used to operating as a normal army and perhaps Israel would take the time to terminate them with extreme prejudice, which is what I would do in their place. There will be loads of Palestinians taking up arms as well.
I can tell you that should Egypt start something, there would be little mercy coming from the Israeli side. Israel has to watch out for a pan-Arab attack IMHO.
I don’t know if you see things unfurling along those lines. I *do* think Israel could find itself once again under assault from multiple directions, on multiple fronts.
The Muslim Brotherhood in Egypt has a couple of problems. The states military is split between secular and Islamic. They just sacked the top positions controlling that military. Their main concern now is too avoid a civil war and to unify the military. War with Israel will solve those two big problems.