Accra Airport: Shopping Questions + More

Hi. I have free time at Accra airport next Friday between 4.30 p.m. and 7.30 p.m. I want to visit nearby airport shopping places (not as far as Osu or Adabraka).

Things I need:

• 2 quality novels (no airport fiction) and current guidebook + map for Gambia
• black olives, sun-dried tomatoes, good bread, other delicacies
• useful presents to bring from Ghana for western + African recipients
• bank/money changer (to change last Cedis back to Euro)
• maybe need luggage storage at airport, if I cannot check-in my luggage 5 hrs prior to take-off

As for the books: should I use Silverbird store in Accra Mall near airport? (2nd hand would be fine too, if near airport)
As for the food: should I go to Max Mart opp. Golden Tulip Hotel near airport? Or is there a good deli food option in Accra Mall?
As for banks/money changers: There is Accra Mall of course. But how about the bank at the airport - are the rates ok, is it not crowded, is it open?

When I fly out, is there any departure tax or other expenditure at the airport?

Thanks for all your suggestions!