TBH bud I wouldnt bother renting a car unless you have places to go, a standard taxi fro Malaga airport to where you are staying will only be about double what I pay to Fuengirola so about 40 to 50 euros. I would suggest you do that and if you get bored and want to rent a car for a day every other shop does car rental. Taxis are pretty good and for Marbella the old legs arent far off the mark.
You are only about 10 mins from Marbella so a taxi is fine. Theres an airport bus to Marbella for 4 euros
Anythink I can arrange would be about the same as a taxi, I really only use pick up services to save people having to try and find my apartment using Spanglish after their flight. You wont have that problem, everyone knows your place, great golf course