Dublin>Kenmare>Dingle>Galway 7 full days itinerary

Personally, I think you are shortchanging the Doolin and Connemara areas. I found them much more scenic than the Dingle area when I spent 3 weeks road tripping in Ireland. If I had a week, I would spend 2 nights in either Kenmare or Killarney. Visit either Ring of Kerry or the Dingle Peninsula for the day. Then 2 nights at Doolin visiting the Cliffs of Moher and a day day circle through the Barren area. then up to Clifden for 2 nights to visit the Connemara area.

I stayed at the Aran View Country House near Doolin (a 15 minute walk to down) and I will never forget the view from our room. Pastures with cows and then the ocean. In the distance was Inisheer Island. So beautiful!
https://www.aranview.com/

I took a day trip form the Aran View to Burren National Park. Walked on of the trails, visited Church, Stone age and Medieval ruins and then saw Black Head Lighthouse as we drove the coast back to Doolin.
https://www.nationalparks.ie/burren/things-to-do/#walking

On the way to Clifden from Doolin, I took the road (R341) just past the Pines Island viewpoint towards Roundstone and back up to Clifden. Such a scenic drive past some beautiful beaches.
https://www.galwaytourism.ie/the-quiet-man-bridge/
https://www.discoverireland.ie/galway/dog-s-bay-beach

From Clifden, a day drive can include a visit to Kylemore Abbey, Killary Sheep Farm (the most gorgeous view of the Killary Fjord which is Ireland's only glacier fjord) and the little town of Leenaun. Back down to Clifden seeing working bogs mountain views and lakes.

https://www.kylemoreabbey.com/
https://killarysheepfarm.com/

Just something to think about if you want to see a bit more scenic Ireland.

It would ease your logistics a bit and save you a long drive across the island if you continued your journey on the 29th by flying from Dublin to the Kerry airport near Killarney on Ryan Air. I see that they have a direct flight leaving Dublin at 2:45 PM that day.
There are a number of rental car outlets at the airport there from which you could do a one-way rental back to Dublin via the Galway/Connemara area.
Though Kenmare is a good base, my suggestion would be to look for accommodation outside of Killarney which will be an overrun and congested mess that time of year. We usually try to stay somewhere along the corridor between the villages of Cahersiveen and Castlemaine for easy access by car to the northern half of the Ring of Kerry, the Gap of Dunloe, Killarney NP, and the Dingle peninsula - allows us to unpack once and be done with it for a few days as well as avoiding the worst of the crowds ... especially with an early start in the morning to beat the tour buses.
Dingle is great but I think you can cover Slea Head Drive and generally see what there is to see in a day.
I'd use those extra days to do as Barbara suggests and spend more time up near Doolin, Galway and Connemara before heading back to Dublin for a day or two before your flight home. We particularly like the market town of Clifden, but you can't go wrong no matter where you choose to base yourselves - it's all beautiful.