First off is it possible to bind actions to either of these buttons? Because if it is possible the only things I'd like to bind to right-mouse-click is pet attack when clicked and mount (alt+right-mouse-click).
The right mouse button is already bound to something you can't see on the bindings screen called TURNORACTION. This is what allows you to interact with objects in the 3d world and to do mouse-based steering. If you re-bind your right click you won't be able to do any of that unless you then re-bind TURNORACTION to something else. You'd have to line up your cursor over whatever you wanted to use and then press that something else.