The walk along the seafront at Crammond is one of the most beautiful and accessible (very wide and flat path surface) I've done.
The carpark is really busy because it is such a popular place to go. There are a couple of disabled bays but just know you might need to find somewhere else to park.
The one negative about this location, and it's a huge one, there is no accessible public toilet. The nearest one I could find was at a costa coffee shop a 5 minute drive away.
The clip below follows the route from Crammond Island along towards Granton Harbour. I turned back at the point I did because I was cold but I'm led to believe the path just keeps going in a similar fashion.