It is nice that you're staying put for several nights in each area.
Without knowing your driving routes and what you plan to see, here are my comments.
Your missing the entire spectacular northwest coast of Scotland. Maybe consider going to Scarfskerry before Inverness so you're not backtracking between the 2 places. But, I would throw in an overnight stop on the way north from Skye to break up the drive. We drove from Portree to Bettyhill (with their fantastic Strathnaver Museum) with an overnight in Scourie in 2023. Beautiful views!
Also, keep in mind driving times will take longer than the Google maps estimates, especially when your around the coast. And driving on the "opposite" side of the road can be exhausting even if you've done it before.
What are your plans for Scarfskerry? There is not a lot happening around there.
I know you're planning on staying in Airbnbs, but don't overlook all the wonderful accomodations in Scotland. We've stayed in castles, in beautiful rooms over the pub enjoying an evening with the locals and a farmhouse with sheep in the meadow and stunning views of the North Sea.
You're going to have a wonderful time in Scotland!