We had a rental car so not sure how much this will help. In Agrigento we stayed at B&B Villa San Marcos and walked through the olive grove behind it to get to the temples. From Agrigento we drove over to Scala de Turchi, but since we just wanted to view it, we stopped just down the road at Belvedere - Scala dei Turchi - F.A.I.. There is a small parking lot and an overlook affording a great view of the terraced rocks without having to walk down to them. From there we drove over to nearby Lido Rossello and parked by the beach near the cliff. The rocks there are the same type formation as Scala de Turchi so we got a close up view. We then drove to Selinunte to see a couple of the temples closest to the entrance. They were similar enough to those at Agrigento that we didn’t go to the furthest temples as they are fairly spread out.
While we would have liked to stop in Mazara Del Valle to see a couple of the churches and Norman sites, we didn’t have time. We spent that night at Hotel Carmine in Marsala. We enjoyed it and it had a good buffet breakfast. It’s in a good location for walking to anyplace in the historic center. From Marsala we drove the few miles to the very remote salt farm. Thank goodness for gps and a nice gentleman working at a service station. There roads were very, very poorly marked. Actually, I don’t remember any markings. We also stopped at the Trapani salt farms before heading up to Erice where we spent 3 nights. The Marsala salt farm was the better of the two. To get to Trapani we took the cable car, then walked the fairly decent walk to the historic center. Photos from that trip are on my website.