Adding some aim time (at least a windup) to throwing would definitely be warrented. The rate of fire is downright silly, at least for a starting character with no skill, bionics or mutations.
I don’t think throwing knives and axes are too good, though. Good, but not unusually so. After dozens of characters I’ve been lucky to find a set of three or so, and usually when I wanted a throwing-based character I had to set up a forge and make my own because sooner or later you lose a couple. For what are basically end-game throwing weapon gear, they’re fine, IMO.
Plus there’s something sweet about strapping a bunch of throwing knives to your chest and stepping out against a horde to reenact Judas Priest’s The Sentinel.