First and foremost you always have to be attentive during setups.
If you get something you don't want, don't blame anybody but yourself.
Having said that there's one detail in the OpenCandy EULA which isn't always true, Point 7. Third Party Software Uninstallation:
We ensure that all OpenCandy recommended third party software which may be installed allows for simple uninstallation without harming your computer, and without leaving files or applications behind.