"Must ticket" means "must ticket," not "must travel." You need only to book your travel by May 1; your travel can be booked to the end of schedule as of date of booking.
You are eligibible for E+, just like on any other flight.
The ticket isn't upgradeable but there's a slim chance you could be offered an upgrade-for-cash, depending on the flight. Of course, whether you think the UFC price is worth it is a different story. You can't upgrade with miles or other upgrade instruments.