Not correct. All men (and women) except those in a Yeshiva (religious school). As I understated it, they can post-pone their enlistment indefinitely.
I also understand this is a touchy subject in Israel right now.
Not exactly true. There are a few different computer groups, one of which requires only three years and it is nowhere near the level of sophistication of an average programmer (they are mostly responsible for the technological infrastructure of the army). The other programs require a degree beforehand (so they only go into the army at about 22) and then require 5 years of service. These are the people who create cool things. But let me say: even the things that they do are closer to things you can think about than what you would find in a sci-fi novel.