inviting users to private polls

1. Is there a way other than emailing a URL that I can invite users to a private poll? Similar to how CommunitySurvey works? For a survey (private), CS supports a number of ways to invite users, while in CP, the only option seems to be using the secrete URL for the private poll and email them out.

2. For the secrete URL for a private poll, aside from getting it after the poll is created, is there a way to retrieve them later? I can't find it from either the admin UI or the front end when logged in as the poll creator.

3. Not sure what the purpose of the "User" tab on the admin backend, CP configuration UI. After hitting "Rebuild", it displays a list of Joomla users and some statistics of the number of polls that they took, etc. I was hoping CP could pick up the users and support invitations to such users to a private poll.

Help is much appreciated.