SC Login via link and not module position

I'm not sure exactly what you mean when you say link. Do you mean a URL you can email out to people to let them login from?

The best way I'd recommend doing that is setting up an article with some instructions on logging in or whatever you want and add the SCLogin module to show in that article. If that article isn't set to show in any blog layouts or menu items, it shouldn't normally be 'found' by users or search engines. You should still be able to link to it directly.

I hope that helps give an idea, but if not, let me know a little more about what you're looking for.

Thanks,
Alex