We did the ACW this past May. A bit too much road walking but still a great trip. Turning right from the ferry works great except at high tide when the trail is under water. We walked the road until we could cut across the golf course to the trail which is generally well-marked and common-sense obvious when it’s not. We wild camped three nights, B&B one rainy day and spent one night at an unpleasant, midgey commercial campground. So five nights, six days.
As you reach the southern end of Aran the way markers send you up to the road too early IMO. It was the worst stretch of road walking we had in our six weeks in Scotland. Not the longest but scariest. I would continue along at the ocean level until you arrive at a second opportunity to make the necessary climb to the road.
You do have to pay attention to the tides on the south end of Aran but it’s all easily managed so long as you’re not in a hurry. Lots of rock hopping around the two points. We lost the trail at Largybeg Head but improvised an easy route down from the standing stones.
Our guide book said a high tide could prevent you from making it to from Whiting Bay to Lamlash but there are new boardwalks along that section so I’m not sure that’s still true. We moved through there very quickly because the almost high tide was coming in but we didn’t have any problems. A particularly high tide might make for more difficulties.
The side trip to the Machrie standing stones is well worth it. We were also quite taken with Lochranza and enjoyed the distillery tour there as well.