Why both Weather Ball and Hydro Pump? Psych Up usually isn't all that great either. I'd give it Thunder and some other move.
Weather Ball is in case the opponent swaps the weather to attempt shutting down a rain, sun, or hail-specific Castform. Its type changes with the weather, so it gives it a flexible last resort STAB attack.
I'm thinking about creating a printer-friendly Pokédex guidebook for Black and White versions. Let me know what you think about it here.