The receiver keeps a list of services. It also has a list of bouquets/favourites. The two are different entities. enigma2 receivers also scan in the background when you are on a transponder, so you will always get changes. Unless you have services for satellites you don't have, I would not waste my time deleting the services you don't want. You would be better off making your bouquets.
OpenATV forces an install of bouquets. I would post a link to a command you can use to delete all services and bouquets. However, it may be confusing at this stage. You don't even have an IP address yet!
It is a steep learning curve with Enigma2 receivers. Do one thing at a time.