1)AFAIK, there will be an online leaderboard that you can upload to. im a bit shaky on details, so i didnt add it - i wanted everything in the post to be as concrete as i could.
2)As for replays, a ghost would be fine for proofing - but only for lap times, not race times in its current form, and we havent really had need for proofing here by the look of things, everyone is pretty honest about their times. I know i have to be - people would be very suspect if i started posting awesome times
Task, the minigun returns as the Proton Cannon. It was described as about 30 miniature Plasma's being fired out of the front of your ship by IGN if i remember correctly. Sounds destructive.
As for the tracks, i wont add them until they have been confirmed.