Do not break the user expectations. When I use the scroll wheel on my mouse the page screws up. As soon as I get close to the bottom it automatically flips back to the top. You may want the user to use your scroll buttons but most people won't because scrolling has been around from the beginning and people already do it a certain way. Expecting them to change for your site will make them leave. You can add your own little nuances like you have but always make sure it meshes with the current way of doing things.