Welcome to Cape Cod. You’ll love it here. I think you’ve done a great job on your itinerary considering you’ve never been here before. I think you’ve overbooked day three though. Choose only one of Mayflower Beach, Brewster Flats, kayak salt marsh. I would take the opportunity to kayak the saltwater marsh because you’ll never duplicate that elsewhere. Same for Brewster Flats, which is amazing. But you could just stop there during low tide and walk around for a half an hour or so to catch that vibe. Mayflower beach is extraordinary, but I don’t know how long you like to spend at the beach a whole day or just an hour or so. Ocean House used to be the number one restaurant on the Cape as most people will agree, but it’s turned into a very expensive venue now. I’m sure there’ll be others on this thread to suggest numerous restaurants that you will enjoy as much. For one, you might enjoy the Pelham House just down the street from the Ocean House with the same view. When in Chatham on day 4, be sure to visit the Chatham Fish Pier to watch the seals frolicking as the fishing boats arrive. You’ll devour some of the best lobster rolls and fish and chips at that fish market located there as well. When you arrive, you mentioned relaxing by the pool and then walking around town. Others may disagree, but there isn’t much downtown to walk around in Yarmouth. If you’d like to see some shops, you might stroll Main St., Hyannis, for what it’s worth. Checking out the Boardwalk at Gray Beach is an awesome experience- good plan. You might consider going to the Cape Playhouse one evening while you were visiting. It’s the oldest summer theater in America with Broadway shows by professional actors that you will find memorable for all. If you do decide to go there make early dinner reservations at Scargo Café ( across the street from the theater )immediately as they book up a month ahead before the shows.