Jazz may not be a genocidal maniac, but he doesn't excercise restraint on his missions. The JJ1 manual does say the Turtlettes (those little turtles that can't hurt you) are babies looking for something to eat. But really, except for the drug and genocide things, EvilMike's version is fairly accurate.
Oh, and I can't believe I missed this, but Devan doesn't actually die. At least, not if the unreleased JJ3 actually "happened".