It was generally believed that Saddam was the best person to be in charge. He wasn't reliable, but he did respond to US interests in their favour. In 2003, the intention had been to create "Saddamism without Saddam". To create a client state in the most energy rich region in the world - another one, that is.
You mean along the lines of better the enemy we know than the one we don't know?
Back to the arsenal of nasty weapons and comment by Dodge, the BIG countries who helped build that arsenal were ENGLAND, FRANCE, and the United States. Most of it secret, and yes, they would have known exactly what was supposed to have been in Iraq. One of the UN Inspectors however said at the time that there is a limited life on chemicals, and that since the boycott against Iraq, after the Gulf War, Saddam would not have had access to equipment and expertise to keep his nasty weapons up to date. I find Dodge's point of view however very interesting, possibly there could have been special deals in exporting it to some of the neighbouring states, or who knows, even storing the them in the neighbouring countries "temporarily"!

Would be very interesting if the US army should depart from Iraq, if those should make their appearance again? Wonder whether Chemical Ali has passed all of that info to his sons and nephews? Interesting times ahead!