Just to mention about installing/removing ccsm. When you install ccsm nothing changes at all other then 2 additional plugin packages are installed. All of the newly installed plugins are disabled by default, so your install is the same
When you remove it nothing changes either, all that's gone is the easiest way to set compiz plugins, whether to improve or sometimes not, & if need be fix.
So if your going to adjust compiz plugins & aren't sure of or remember your changes then probably better to create a new usr. You can fool around all you want to see what's what.
When done or if things get stuffed just delete the user.