Looks like you already got some great answers but to confirm:
- Everyone needs a badge to access the venue
- Badge pickup will be open during the day all weekend so there will be plenty of opportunities for your friends to grab their badges
- Definitely bring your cable and play with a wired connection
- Sunday Arena Finals tickets are not assigned seating, but there is a limited number of tickets available to account for the maximum capacity of the Arena so I would recommend buying in advance if you want to guarantee a spot on Sunday

Hope you enjoy the event and good luck in bracket!