I did the cruise 2 weeks ago, and we took our own food and beer on, the rule just means you can't eat it in public areas, so yes, your cabin is fine.
Food is expensive as fook on there, cheapest thing you could get was a margarita pizza for £13. There was nothing in the way of burger outlets or any food whatsoever cheaper. Even the duty free shop was expensive. Buffet and breakfast buffet were expensive, we just took cereal bars and bought a cuppa on the morn.
RE: my TV question, there is a sports bar onboard, but it only shows game on Freeview and also Eurosport - basically no PL, but can show FA Cup etc.
Worth buying your Amsterdam bus transfer tickets in North Shields when you check in. £6.50 each way, as appose to €10 each way if you buy on the bus.