Never Mind
Consider, we PAID for the software, so WHY ARE THERE ADS ON IT? I have no doubt Norton has a deal where they allow the aforementioned sites to be LOCKED onto their homepage for a price, which means you do NOT own the software for which you paid.
First you did not pay anything for the Safe Search extensions. It is free for anyone to use whether or not they have a Norton security product subscription.
Second, you are obviously correct in that Norton would be getting paid for putting those links into the Safe Search interface. As you note your cannot remove those icons. The second row of icons can be customised for your use.
You say you cannot remove Safe Search. How are you trying to remove this extension? There should not be any issue removing using the Manage Extensions feature of your browser. Do you get any error messages when you try to remove these extensions?