Yes, CC you've named just a few.
Cape Breton, top of that island, Meat Cove. What is outside the Cape Breton Highlands National Park is far more pleasing, IMHO, than that in it. Cgs in that park are far tooooooooooo squish.
Give yourself something like 2 1/2 days for Fortress Louisbourg, there are many things to try to take in carefully in that rebuilt town/fortress. Different types of eateries of the historical era, ie. the ordinary for the labourer, and the the more posh for the officers. Still you can dress as casual as you like for either.
Whycogamagh Farmer's Daughter store and eatery
Getting there: drive by road or ferry across to Yarmouth. IMHO drive. But you might want to drive from Lubec, ME to Campobello Is, then boat to Deer Is., NB, and on to Grand Manan, NB before going across to the mainland of NB. Of course, you miss Calais, ME and St. Stephen, NB going that route. Maybe go up one way and come back another.
NB Mactaquac, Acadienne Historical Village, Kings Landing, Hartland Covered Bridge (longest covered bridge on the blue planet), Saint John City Market....
NS mainland, Historic Properties, Halifax, Ovens, Yarmouth Museum, 5 Islands Prov. Park.....
PEI: take ferry to, leave by Bridge - pay on leaving, bridge costs less. BEST LOBSTER meal in all Atlantic Canada (meaning NL too),
New Glasgow Lobster Suppers, Orwell Corner living history village, Sir Andrew MacPhail Estate (tea room), Charlottetown Farmer's Market go with empty fridge and empty tummies, and crafts. & beaches if you like.
:B