On the coolant elbow seals. Why would you tell him to order more? There is a set in the LIM gasket kit, and the elbows he ordered will come with them on the elbows. That's two sets. If you guys are blaming the plastic elbow as the failure in the elbow area, then why buy more o-rings when he'll have two sets? Silliness in my mind.
You asked why the red and blue seals in the LIM gasket kit. The answer is in this link, basically it's old casting of block vs new.
http://www.grandprixforums.net/lim-g...ign-39522.html (LIM Gaskets: First and Second Design)
Throttle body, it's a gasket and you should get it. Also get a can of TB cleaner to clean it while you have it off. This will make your car run better and have better throttle response etc.