Hi Mate,
I have been living down here a while.
Cigs - grab them in Gib if you can get them - otherwise the price down here is generally much cheaper then in the UK - about 3e a pack.
There are several car rental places at the airport - I usually refer friends coming down to tony's rent a car - they are located just over from the airport, but they actually meet you at the airport entry area. If you state the need for a wheelchair they will probably come with the car right to the exit.
Not to sure about the places to eat.
As tyo what to do - there are loads of activities.
I usually like going to the safari park - it's south of Malaga, and called Selwo Aventura - pretty cool - but overnighting there is expensive - but I did it once - and was great.
Hope you have a great trip.
Pete