Honestly way way too much driving. Why fly into Belfast if your not exploring the area ? Fly instead into Shannon and your in the west. Assuming you want two nights in Dublin at the end. That gives you 5 nights to explore the West a bit.
You can't cover Dingle and the ROK in 5 days, let alone Ireland. Trying just leads to hectic one night stays and a frantic pace. Less is FAR more in Ireland. Depends on what you want but if you want history, insane scenery, pubs, real wild Ireland and a chance to really soak in Ireland as much as possible, skip Galway (it's a city, a nice one but you'll be in a city at the end). Also skip Cork and Blarney Castle. It's a long drive to wait in line to hang upside down and kiss a stone - there is so much more to see in places you would be near. Unless it's a life dream it really isn't worth it.
Would urge you to fly into Shannon and pick two spots to stay and see the west. You could easily do the Cliffs of Moher......though the Cliffs of Kerry on the Skellig Ring are far more wild and less touristy....and if you are on the Ring of Kerry it's right there. See Dingle and Slea Head and the Ring if Kerry and the Skellig Ring. There is enough to fill weeks in both places let alone just 5 days.....Cliffs, great small villages, castles, ruins, ring forts, standing stones, pubs, truly incredible scenery, the Blasket islands, Skellig Michael, being in a UN dark sky preserve with some of THE WORLDS best stargazing, shopping, trad music in pubs, hiking, horseback riding, and the best folks we have run across in a Gaeltech language area. Truly incredible......and by cutting back on the driving and one night stays you give yourself time to soak it in and enjoy it instead if being in a car all day.
Anyway ...Just our two cents worth. Hope you have a great trip.