Belkin is a "value" brand of router and has few options you can do little other than buy a different router. Most belkin do not even support third party firmware.
I can see you don't want them on your lan but it comes to the question of if you can not trust them to not do bad things on your lan why would you trust they not do bad things on your internet connection. In the end it is you that will be responsible for anything done from your account.