Very nice program, the 10 minute modern piece does not appeal to me, like the first part a lot! I like the mixture but i think a debussy piece would be nice, and instead of a rachmaninoff etude, a prelude, but that is my opinion.
For the modern piece, do you mean from 1900, onwards or modern as in 1990, onwards. As a Joplin rag would be good, but it depends what you need. As far as 10 minutes goes, i think a joplin rag and prehaps a boogie or blues, but i know that is not slow, but slow performances can sometimes bore an audience, + i dont know if you want to keep it classical, romantic theme? What about satie gymnopodie no1, if know its easy, but always a winner!