Your SourceCoast Subscriber ID can be found from any of the menus under the "My Account" menu in the top right. Choose My Profile, My Subscriptions or My Downloads and your unique ID will be listed on any of those pages.
For the auto-login on mobile, can you tell me if you have a special mobile site, or if you're just testing your site from a mobile phone? In general, the mobile auto-login should work just like normal, but you need to be logged into Facebook.com (not just the mobile Facebook App) in your browser. If you're still not able to auto-login on mobile, let me know what device and OS you're using and we'll gladly help investigate further.
Finally, regarding your subscription, we're glad to have you back! You wouldn't be the only user to subscribe, get a refund, and later realize what you were missing out on.
Thanks,
Alex