Just from looking over this topic I think this is one of the best ideas you have had yet. I think that a straight track prototype would give you a good indication about the efficiency and seat rotation of your train. I remember seeing the prototype for X which more or less was a straight track that had a small hill to test just these things. Good luck with the project and I hope the train works out for ya...it's quite an undertaking.
Can't go wrong with Busch Gardens in Williamsburg...absolutely gorgeous park. Gotta love being down on that river seeing Alpengeist and Nessie, and of course this season Griffon will just add to the beauty.