I know my opinion is more than likely going to be in the minority but I am okay with that. I think it's irrelevant that your asking about a Costa tournament. The real question should be can a P2 handle Big O, Chick and Santee. The P2 is plenty big enough for two people to tournament fish out of. It also plenty big enough to fish any of the three waters you list. Now there is a possibility the water can get rough and in this case you will have to know your ability to maneuver in rough water as well as the boat's ability to maneuver in rough water but the P2 is plenty enough boat for the waters mentioned. On a real rough day a 25 ft offshore boat would take a beating on the big O. It's all about knowing your ability to drive the boat to its full potential and then know the boats limitations in rough water.
By no means am I bashing the OP because that is not my intent. I just think people get caught up in what they need to fish a tournament. Yes there is advantages to a 21 ft boat with 250 HP duel anchors a 4 graphs with SI,DI, 360 and panoptics and all the latest technology. I think what has happened over the years is the public has been made to believe you need bigger and more advance stuff to compete. It would be foolish to say it does not help however I am not convinced you need it to competitive.