I used to work at Donny airport however i am unsure about the current restrictions regarding hand luggage and whether Donny is really strict about it. If there is any comparison, they used to be really strict in terms of excess baggage weight and is was quite expensive to pay for extra.

With regards to the shops.. the majority of shops are before you go through security and what is called the viewing area. Downstairs there is just a spa and a costa coffee..

upstairs there are the usual coffee shops and eateries and then once you are through security there is a newsagents, a duty free shop that sells fags and perfumes, bling, chocolate and booze etc more eateries and a coffee shop and an amusement arcade. If you want to buy toiletries, your best bet is probably the spa downstairs in the hope that you can get them through security. The newsagents may sell lippy and stuff and the duty free may sell cosmetics but i seem to remember prices were extortionate once you had gone through security..