Dingle is one of our favorite places, but an eight day trip is too short to include the farthest point from Dublin. We made a trip like yours ten years ago and although we enjoyed it, it was tiring amounts of driving and we returned home exhausted.
The first day is shortened by a long flight, unless this is part of a bigger trip. Leaving Galway on the day you fly out is risky, unless you're headed somewhere besides Seattle.
You'll only have 1/2 a day at best in Kilkenny, then a long drive to Dingle, which gives you one full day in Dingle. Another long-ish drive to Galway, meaning one full day in Galway and early departure for flight?
First time driving on the wrong side?
Every drive will have innumerous stops to see ruined and intact castles, gorgeous gardens, waterfalls, Neolithic sites, museums, folk villages, and viewpoints.