I've driven around Ireland 3 times and this schedule is possible, but Day 2 is going to be a nightmare of a long day. Also, the Ring of Kerry is a tight road and in June there will be plenty of buses so it's going to be a very slow go. We much prefer the Dingle peninsula. It's a much less-traveled road and Dingle is a great party town- loads of pubs with lots of singing (and much of it in Irish).

I'd also suggest spending the night in Kinsale instead of Cork, and (if you have any energy left), stop by the Rock of Cashel on the way from Waterford to Dublin. It's only a few extra miles and the Rock is much more interesting than Kilkenny.

Just remember this simple rule when getting advice: the Irish think 100 miles is a long way, just like Americans think 100 years is a long time.