I understand where you are coming from and the reluctance to clean automatically, however I have to disagree with the people who think that it is any safer for a person to manually click delete than the program to do it.
99.9% of people (including myself) do NOT fully understand what the impact will be of deleting everything that is being presented. The only people who truly do are the ones that wrote the program to begin with. And isn't this the reason that most people use a program such a ccleaner in the first place?
With that said, I would never delete or even modify the registry without making a backup prior to doing so. This at the very least reduces the chances of a catastrophe from occurring in the first place and gives you a chance to reverse any damage done.