1) Just set things straight.
2) You can go to HDDR and see if a walk-up is available for that show.
3) There are people who back out at the last minute or no-show.
4) I cannot give you a percentage, but several times a week, walk-ups get in.
NOTE: Do not expect to get in for vacant Cat-1 seats if you are on DDP, unless you pay OOP. They will not violate the rule, or it sets a dangerous precedent. They want the extra cash a Cat-1 seat delivers and do not want DDP people to use a past incident as a reason to argue for a Cat-1 seat.