Calci-dust should be pure (i.e. no D3) as yes, it can be overdosed. The D3 in the nutrobal and UVB light should be enough.
People differ on the whole water bowl thing. I'd provide it (keep it on the cool side) so it's there if the dragon needs. Other people decide to bathe them often instead of providing a water bowl - I would tend not to do this unless they look dehydrated (particularly with a young dragon) as it can be stressful