I agree with your assessment. As for the gas situation, it did turn out bad. While I disagree with the thought of using gas there, it's a heck of a lot easier for me to arm-chair quarterback on this, than to make the real life or death decision.
When terrorists take over, the blame for bad outcomes is on them, unless the government involved makes a very poor judgement.
The gas plan was a good try, but it does seem the pros and cons weren't studied enough in preparation. Still, what sovereign nations do within reason, is an internal affair. The gas plan certainly fell within those parameters as far as I am concerned. Perhaps another gas could have had a better outcome.
Less people died when they gassed the theatre, but there were more children in this setting.