Maximizing a SHORT trip

We are trying to maximize a short (5 available days only - day of departure not included, but arrival day is!) spring break trip. Our graduating senior picked Ireland based on his interest in Medieval history & we are working with the time constraints of 2 different school schedules. The travel group is mom, dad, & 2 boys (18 & 20) - good travelers & used to packing a lot in to short spring break trips (sometimes the only time our schedules line up!). Renting a car - dad likes to drive & has driven in UK several times before ,but not in Ireland. We don't mind a busy itinerary, but would like to slow down in the evening for dinner &/or music. The graduating senior likes sea shanties!

So far, the rough Itinerary is the following:

Day 1: Land AM Sun 3/15 - pick up car, visit Trim Castle on way to Kilkenny (looks like they are only open on weekends during this time period, so this is the only day we have to do it) & son interested in Medieval Mile - dinner will be in Kilkenny, TradFest is going on - staying overnight, but only this night.

Day 2: Mon 3/16 - Head out for a long day on the road - Rock of Cashel, Ring of Kerry (up in the air as to which stops) & then on to Limerick. Husband enjoys drives, so this is his "driving around" day - dinner will either be on the way to Limerick after the Ring drive or in Limerick. Staying in Limerick.

Day 3: Tues 3/17 - Husband would like to visit Cliffs of Moher & son is interested in King John's Castle, Hunt Museum & seeing Medieval Quarter - this day is flexible & we realize it is St Patrick's Day - we are staying in Limerick this evening, but heading out to Dublin the next day. Does anyone have advice as to how to organize this day?? Not sure of the impact of St Patrick's Day on what we want to do (this just happens to be the dates of our spring break & not WHY we are there)

Day 4: Wed 3/18 - Leaving Limerick for Dublin

Day 4 & 5 (Wed/Thurs) are our only full days in Dublin before leaving on Friday - trying to determine:

How fast should we leave in the AM to get to Dublin on Wednesday in order to see what we want to see in Dublin? (so far Kilmainham Gaol, Guiness Storehouse, National Museum of Ireland - both locations are of interest, Epic, Trinity College are on the list!)

Is there anything we should consider adding to our list on our way from Limerick to Dublin or should the priority be getting to Dublin?

How flexible can we allow ourselves to be in Ireland? Is there any site of interest above that we absolutely MUST buy the tickets & work our day around? I ask because we have traveled to places that felt like everything needed to be planned to the minute in advance & other places where we were able to plan the next day at our evening dinner with no required advance tickets. I'm not sure how Ireland rolls as this is our first trip there!!

THANK YOU!