I'm not so sure about character creation, I think it should really stick to the Nero/Vergil/Dante/Sparda/Whatever character slots, but I really do like the idea of Devil Arm customisation, creating your own weapons sounds like a great idea.
I do like the idea of making the player feel free to customise what he or she wants though, a lot of people appreciate stuff like that, it gives the feeling of an open world aspect to the player, I must admit, I'd buy it, but that's because I do love the whole free reign customisation aspects of games. :lol: