LainieH - You concern is valid and could have been resolved by LiQL. If you go to this article and look for the registration status, there are 3 types of users, Anonymous, Partially_registered and Fully_registered. You are looking for the Fully registered users. Unfortunately the LiQL doesn't allow you to query on this constraint to pull out only the fully registered users alone. There is an idea already posted for this to use anything as constraint, please add your support to this.
As of now, there could be a workaround for your first case where you want to display the fully registered users but would not be effiecient. You could query a bunch of users and filter the fully registered ones, but as I mentioned, that would not be an efficient way because you might end up calling first 100 or 200 users and still not sure if 14 of those would be fully registered ones or not.
