In reply to Brilo:
A quick google to see where this trail went yielded several bits of info including answers to many of the questions you posted.
I haven't done the trail but I know the coast of that part of the world quite well. The coastline and the settlements along it are really pleasant places to be and the route between Honfleur and Le Treport will be constantly up and down. If you walk the beach between Yport and Fecamp don't get the tides wrong! I'd recommend a stop in Fecamp, best place for food and balances being a 'real' functioning fishing town with being accommodating to tourists as well.