Restrict sub-site admins to only edit certain marketpress settings

I am creating a site where I want all almost the sub sites' store settings to be all the same. There will never be any shipping, downloading, etc so I don't want them to see or change almost all of the marketpress settings. Really the only thing I want the admin's of the sub sites to change is their paypal information so they can get paid. Is there a way to hide tabs on the settings page, and/or fields on each of the settings tabs? If not, is there a way I could build a plugin to just them them enter their paypal information only, and have it update the database with it?