I think you could do a lot more each day. Your proposed schedule seems a bit light on hiking. On June 24 you could go straight from sunrise to Jordan Pond. There you could easily hike Penobscot Mountain with time to spare before your reservation at the Jordan Pond House. The views from the top of Penobscot are wonderful -- long summit of open granite. Here's a description of the hike: https://www.citrusmilo.com/acadiaguide/penobscotmountain.php

There are many more hikes described at the above web site. The Beehive Trail you had scheduled for that day could be easily done the day before along with the Ocean Path walk.

There is a grocery store in Southwest Harbor. But you might do better stopping in Ellsworth on your way. There is a Hannaford and Shaw's grocery store in Ellsworth as well as a Super Walmart.

I think the nature cruise from Northeast Harbor would be better. Northeast Harbor is a sailing town. The harbor itself is interesting and there are lots of little islands as you boat out from there. One has a huge osprey nest. You could explore Northeast Harbor that day as well as take a walk through the Asticou Azalea Garden and Thuya Gardens.

It's about an hour's drive from Bar Harbor to Schoodic. If you are up for a longer day of exploring, you could also go up to Machias or even all the way to Lubec.

On your unscheduled day, you could explore the back side of Mount Desert Island: Southwest Harbor, Wonderland and Ship Harbor Trails, Bass Harbor lighthouse, Thurston's Lobster Pound. The Blagden Preserve at Indian Point. https://www.nature.org/en-us/get-involved/how-to-help/places-we-protect/indian-point-blagden-preserve/

Lots to do. Take a look at http://www.acadiamagic.com for ideas and great photographs.