Howdy John,
What you want is definitely possible as a customization. I have a snippet that can be modified with great ease, especially if you are familiar with WP User Roles. Simply put, that snippet allows you to selectively hide event categories (and the events within) from some user roles. So, for instance if you have some events that you only want registered users to see, then you would put all of those events in a category, or even multiple categories, and then hide those from guests by modifying the above.
Does that make sense? Will that work for you? Please let me know. Cheers!
– Brook