How can I use the management shell to display all forwards a mailbox has applied to it ?Also, once viewed how can I use the shell to remove particular, or all, forwards listed ?

If you have Exchange 2010, you can use get-inboxrule to find all the rules, and then check those for any that have ForwardTo, ForwardAsAttachementTo, or RedirectTo actions set in the rules. From there you can use Remove-InboxRule or Disable-InboxRule to remove or disable those rules. [string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "