Aww Chewy sound lovely. Don't worry about her not pouching. Not all do and it does take them some time to settle and get into a routine where she will probaly pouch and store her food once she has established a bed, store and toilet area. This can take a while and they often change their minds frequently and you should let her decide for herself.
Hamsters don't really need to actively chew a lot to keep their teeth trim. As long as they are properly aligned they will wear against each other as she eats and keep to the correct length. This is actually surprising long if you ever see her yawn.
Overgrown teeth will present with symtoms such as difficuty in eating, weight loss and often drooling from the mouth so as long as she does not have these then don't worry. Hamsters do not normally need teeth clipped unless misaligned. You can offer her hard dog biscuits to chew if you like and they do usually enjoy these.
Her diet of hard seeds and nuts and maybe some semi cracked shelled walnuts will see her teeth fine.
They all like to chew cardboard and this is fine. She won't be swallowing it but if you watch she is likely chewing it into little bits to soften it and will add it to her nest. She may pouch the bits to take them in to the nest.
Ours like the sand bath too and use it as a toilet.
Don't clean her out too much to start with as she needs her scent to keep her unstressed. I would do a full clean every two weeks with a baby and clean her wee corner every few days. When you do a full clean always put a little of her old bedding back to keep her scent and help her settle.