Clearing the Cache..

A quick question. Does it remove any downloads such as map packs or arcade games?

I know it deletes all temporary files but I am worried that I'll lose important stuff.

Well to make it longer then shall I ask why the clearing cache didn't really do much? My dashboard blades still take about 4 seconds to load and when I scroll through my lists it freezes every now and then which is REALLY annoying when you are just trying to quickly message a friend..

In my opinion, it shouldn't freeze at all when you are scrolling through your friends list.