It's not rocket science to figure it out. It's easier to kill your enemies and reduce damage to infrastructure if you use chemical weapons. And, with Russia's help, he has gotten away with it quite a few times.
The conspiracy nonsense is 9/11 truther crazy.
Doesn’t do any good.
Assad was already kicking Al Queda’s asses. He was not in that much of a hurry.
The only result if such an action would be totally anti-Assad, predictably. To kill a few dozen men, women and children? Come on.