If you do go to Slapton (and you should), there's also the Tank Monument, in recognition of the US servicement lost during rehersals for D-Day. Make sure you eat at least once at The Start Bay Inn, you'd struggle to find fresher seafood (the chef buys from a boat on the beach), certainly great value for money. A little further down the coast you'll come across Hallsands: a villae that was literally swept into the sea
Visit Totnes and walk around the town that told Tesco to fook off. Nearby you'll find Buckfastleigh, buy a bottle of Buckie and sit on a park bench, pretending to be Glaswegian
There are plenty of good coastal walks, google really can be your friend