I was lucky enough to live and work on Sal for 4 months at that windsurf centre at the Riu. We fished a few people off Ponta Preta, myself included. Rescue charges varied dependant on how grateful the rescue person was, and how many cheese toasties/beer they bribed us with. It used to be operated by Scuba Caribe who have the diving centre contract for the Riu, and they were always more than happy to pick people up. However if its really big, they don't launch their boat because of the monster shore break, so beware!
Santa Maria is very safe, Cape Verdeans are friendly and respectful people.
There are plenty of places in town which offer really good food as well. Odjo d'agua north of the pier does great seafood. There is a pizza place hidden in the new developments not far from Pirata as well.
Sal is a great wave spot when it fires, but for freestyle there are way better places to visit.
One of the most underused and underrated kite spots on Sal is Punta Leme, downwind of Kitebeach/Shark bay
This has fantastic wave riding and flat water. The launch is sketchy mind you, but you can come downwind from Kitebeach. It's a cheeky little left hand point break.
I would swerve the hideous all inclusive personally and stay at:Porto Antigo.
You need to hire a 4x4 to get anywhere really. We used to use either Paulo or Tequila. They are both top guys! Paulo was the fastest and most drunk, and Tequila was normally fairly sober and slow. Ask around in town and you will find them. Its a small place.
If you have the opportunity head for Sao Vicente. 2 years ago it was completely underdeveloped for kiting. There are massive beaches and some lagoons here if you look hard enough.
Salamansa has some amazing waves. Its a monster shore break with a pool in front of it! Mindelo is an amazing city full of cool architecture, music and good food.
This has made me feel very nostalgic. After 4 months there we were pretty fried and had islanditis, but I would love to go back at some point!
There is also more about Cape Verde on my blog in my signature.