I'm not sure I understand your issue. A user not logged in doesn't have a profile so they can't view their profile to subscribe. They need to go to Registration or the plans URL page below to list all available plans (the plans must be set to display on registration).

index.php?option=com_comprofiler&task=pluginclass&plugin=cbpaidsubscriptions&do=displayplans

If still not displaying on the above URL or on Registration then ensure the Subscriptions tab in CB > Tab Management is public and published. If still not displaying then ensure you're displaying plans on registration within CBSubs > Settings > Global.

Yes, it's possible. You can use the above plans URL to send them to a page that displays all available plans to them or they should also see plans available to them on the Registration page. If a user attempts to access a location protected by a subscription they don't have then CBSubs automatically displays to them the subscription they need (this assumes everything is set as Public so CBSubs can do the access check and not Joomla). You need to ensure your CBSubs plans are configured properly. They should be set to display on registration (see Workflows tab) and be Publicly accessible (see Access tab).

Configuration looks correct. Yet none of your plans are displaying on registration? Please ensure the Subscription tab within CB > Tab Management is enabled, published, and public. Next navigate to CBSubs > Settings > Global ensure "Show subscription plans at registration:" is set to "Yes".