Hello Daniel,
Thanks for contacting us.
Based on your input, I believe you are asking if you edit certain properties in the Advanced Tab, why the properties are adjusted in the designer and vice versa. If you set BookMarkEnabled to false, as an example, why are bookmarks disabled in the designer? Some of the advanced tab's properties are controlled by the designer and we made the designer to make editing these properties more friendly. In our Sitefinity 3.0 version, for example, setting up the news was more difficult because there was no designer and you had to set properties similar to what you're doing with the advanced tab. So, setting the BookMarkEnabled to false is the same as switching off the book mark option in the designer.
I hope that I have understood and answered your question clearly. If you have any questions, please let us know.
All the best,
Joe
the Telerik team