marketpress membership userrole editor.

Membership appears to have a lot of functionality i dont need. My members wont be paying for membership.
And I'm actually using gravity forms to handle the subscription. So people can create a shop and are automatically assigned the role of "seller". So now they need to be restricted to just adding products. I'm not trying to restrict any page on the frontend of the site. Just in the admin area. But rather then just hide admin menus, I'd rather sellers to be properly restricted. at the moment i am unsure of how these plugins work together (although its still new)..So based on what i have written is it possible to get a bulleted list of the steps involved to set this functionality up? cheers