So I'm aware this will add nothing to the debate however I think it's fair to say that no-one here REALLY knows what's happening in Syria. I would however think that Assad has probably used chemical weapons, banking on the fact that countries will hesitate to intervene based on the relationship he has / is perceived to have with Russia and China.
Unfortunately all nations are stuck in a very difficult situation... They act and people get angry that they acted. They don't act and the same people get angry for not intervening.
And then there's the danger of displacing Assad, creating a power void within the country and Syria turning into another Egypt.
Certainly not somewhere I'm planning to holiday anytime soon!