Cant wait to hear how you run Dark Sun. Also yes keep the ability scores it says to use for it, the games balanced around it hence all the weapons are like -1. F yo +1, here's a -1 one wooden club. It's made out stone.
It'll likely be years before I run that. My players like me to keep running the same game. I'm on 18 months on this one. Then I will be running Savage Worlds Cthulhu, then likely Within the Ring of Fire, so it is hard to say when I will get to Dark Sun. I am looking forward to running it.