[SimonandSyril]

This does seem quite normal, but what food are you using? some mixes tend to be bland and don't appeal to some hamsters. Maybe try adding some interesting food items to your hamster's diet (in moderation of course) maybe try some mealworms or various seeds or maybe a few nuts here and there. As far as the nesting problem goes I don't think it should be a cause for concern some hamsters have different ways to cope with drastic habitat changes (it might just be a way for him to navigate his cage)