To manage your invites:
Log in and go to your my profile page (Click on name in header or footer, depends on skin design)
View your invited players and see their status - make sure you're on current season tab
Remove players/add players and send out reminders
To edit invited players email address, remove the player and just add them back with the corrected information
To increase your team size click "edit" next to your team name, make change and click save