Is it possible to connect a users information gathered through this plugin (e.g. name, email address and postcode) to a voting system like http://www.corejoomla.com/polls.html (community polls)?
For instance i would like to know the name email and postcode of everyone that voted on a certain issue and how they voted across other issues.
It depends. The name and email address would be part of the core Joomla user account. As for extended data, like zipcode, that would have to come from another component that the user's profile is imported into. Right now, JFBConnect imports profile information into one of the compatible 'community' components, currently: JomSocial, Community Builder, and Kunena.
So, you should be able to use core Joomla functionality in conjunction with looking up the specific fields you want from your profile component of choice. JFBConnect wouldn't really be involved in these steps. It's job would be pushing the updated profile information into these components so you can use it how you wish.
Hope that helps clarify.