Haven't had any problems yet, but you are probably right. I did back up beforehand, and it was worth the risk, as I didnt need my wife seeing some of the videos I had watched. But yeah, one probably shouldnt be messing with the finder.
Go to system/library/coreservices/finder Right click and select "show package contents" Open contents/resources/cannedsearches/ Beware, only delete those files that you dont need, as trashing seems to actually delete the file, just as deleting it out of the sidebar would.