Itinerary order? Cork/Kerry days

Is this your whole trip?
Day 3 sounds like an absolutely nightmare. I would cut Killarney and start the ROK in Kenmare. This will still be a very long day in the car.
Day 5 also sounds very ambitious, as well. Depending on the time of your flight out of DUB, maybe stay that night in Athlone?

We are not flying out of Dublin til later. This is the "road" trip.

I've actually been to all of these locations in the past (except Cobh and Fort Charles). My partner has not been to any.

We are only committed to hotels and were going to make tighter choices based upon weather.

That is ambitious G3rryCEE has already flagged up Days 3 (completely unworkable) and 5.

I’d also add Day 2 in as well. You are looking at around 5 hours driving time BEFORE factoring in time for any stops and sight seeing. If you are planning to pass through Kilkeny and Rock of Cashel without stopping then fine. You need to allow 1-1.5 hours to visit Charles Fort.... I’m not quite sure you are going to have time for lunch!

Sorry My original post clearly lacked clarity

Day 2 -- Kilkenny or Rock of Cashel - not both

And, yes Day 3 is an issue - hence the post. Trying to figure out where to focus/what to drop. We are fairly flex in terms of what we see -- if weather isn't cooperative we will likely not drive the Ring of Kerry. If weather is good, Kerry Cliffs would be on the list.

Day 5 We have 8 hours to fill and are fine with driving 2.5, stopping 2 driving 2.5 -- or driving 3 stopping 2 and driving 2, etc We know its a five hour distance day and both have left side driving experience. Not entirely sold on any one stop over another though neither of us has been to clocomoise (spelling?) but it's also most out of the way.

Day 2 - OK either Kilkenny OR Rock of Cashel. That means you can probably have 30 minutes off your total driving time. Are you planning to stop and explore either of these places - and how long are you planning for that? Being realistic you need to allow at least two hours (and don't forget to add in time to find soemwhere to park and what about lunch? That is beginning to look more like 3 hours... You need to be at Charles Fort by 4.15 AT THE VERY LATEST otherwise you won't be allowed in. It closes at 5pm so that would be a very quick scamper round.

So yes it is beginning to look feasible although you will have to keep an eye on the time ands any traffic problems could scupper your plans.

Day 3 Driving from Cobh to Nenmare, Cliffs of Kerry and then on to Dingle is going to be 6 + hours AND then add on time for stops. That doesn't include Killarney. If you back track to include Ross castle and Muckross that is going to add another hour to those times. If you are wanting to view the inside of Ross Castle, then the last tour is 16.55. The outside can be viewed once the castle is closed. Last Admission to Muckross House in April is 4.40, although there is access to the the grounds after this.