Ever heard the phrase your enemy's enemy is your friend? They don't have to be bossom buddies, they have a common enemy, and this is war. In a war, friendship doesn't mean squat, you help out anyone who is an enemy of your enemy.
I'm not so sure about WMDs being found, but he clearly had them previously, because years before Bush was even president, people were insisting he did. Hell even the UN did. All of a sudden, Bush wins the Presidency controversially and people change their mind, simply because it's Bush.
I put it to you...if you have weapons worth billions of dollars, and the US Army is on your doorstep along with some chums, would you sit on them? Before you say "Why didn't he use them?" there's a simple reason. He used Scud missiles initially, then there was a bit of a backlash against the UN because according to the report he submitted to them, he didn't have scuds anymore. Liar liar pants on fire. Using just one WMD would've brought every other major superpower into the war...hardly a smart move.
Saddam's best weapon against the invasion was home (ie American, British, etc) opposition to it. This would go if he used them. Could you imagine the US media still opposing the war if he'd used one? Exactly.
So you can't use them...so what? Here's the thought...sell them?! If he managed to ship billions of dollars worth of gold bullion out of Iraq (and he did as they caught a couple of trucks moving gold over the border and these were not the only trucks of similar size and design going the same route at that timeframe) would it really be that difficult to sneak a few vials of a biological weapon out? That's an even smaller mass to get past pretty lax security.
This "Bush is greedy" line is odd...in what sense? PLEASE don't say oil because then I'll know you're stupid because economists have conceded that after Iraq is rebuilt, it will still take 5 years of US investment to actually make the oil fields profitable. Hardly a smart move considering Bush will be out of the White House by then.