To get the Logged in People report

Without knowing how your site works, that is hard to say... 

You said you have a hashed value in the URL for logged in users? What happens if I take that URL and load it in my browser? Will I be logged in? Will I be redirected to another page without that hash telling me that I am not logged in?

Typically what I do is I have a HIT level variable (either a prop or an eVar) that tracks "login status"... depending on the complexity of the site, I can either read from cookies/session variables to determine if the user is logged in.. or if there is additional logic to the site (such as there is code that checks for a valid authentication token to fully determine the logged in state), I then ask the developers to add a login status into my data layer (true/false, yes/no, userId exists / doesn't exist)... whichever method makes the most sense for the implementation, then I track on each page if the user is logged in or not... then I can create segments based on that.

Since you don't have a dimension at this point, creating a proxy is a good alternative, but you really have to understand your site behaviour to understand if there is a possibility that someone could have a hashed value and not be logged in.....