Yes, you should play at the informal recital. If you play one of those Spanish composers that are new to many (and that you play so well), it will also break the ice since listeners will want to know something about the composer. (It's an old party trick - play something no one knows so they'll talk to you later.) Rainer's right about difficulty; but I think that the Rachmaninov is pretty difficult. I read through it again after I heard you play and my fingers kept getting tangled (and I got a headache). You chose very entertaining stuff, which is not bad because it makes it easier to remember your performance. He's also right that you should be more assertive; you probably have more recordings than the other competitors combined, so you're no novice. You should be on a bench in front of an audience entertaining them; it's your rightful place. Anyway, have fun at the rest of the event!