Southwest Ireland Transportation - what am I missing?

I haven't been to Ireland, nor have I driven in Europe, but I want to warn you about one possible complication mentioned in a few earlier threads on the topic of traveling by car with a large group: It seems that in many (all?) countries, you need a special type of driver's license if you rent an especially large vehicle. You're going to need a vehicle that seats more than six because you have so much luggage. The question is whether the type of vehicle you need will be so large that a normal driver's license won't be sufficient. Since this could be a major issue, I'd recommend talking to the folks at one of the major consolidators (AutoEurope, Gemut, Kemwel) to see what they say.

We toured the UK and Ireland in a Toyota Tarago "Spaceship" camper. We were living in it for 7 weeks but in it's normal life it would be an 8 seater. No need for a special license. Fitting all the luggage in might make it pretty squeezy but worth thought.
Easily handled the tightest of Yorkshire, Scottish, Welsh and Irish super narrow single lane roads. A breeze for us Aussies maybe a bit more challenging for Americans.
I think the latest version might have a new name.

You have a big challenge ahead of you! Have you been to Ireland before? What are the must see, must dos for your parents? How long is your trip? How active are your parents?

Perhaps focus in on a few places that are accessible by public transport and really enjoy those? Have some bases where you stay and then rent cars or hire a driver for day trips without luggage. I think for your trip you may find that less is more.

Ireland is small, so unless you've found a good option for flights to Shannon, it's probably easier to fly to Dublin. And if you are trying to fly to Galway, that hasn't been possible for many years.

Train travel is certainly an option, and you don't need to travel via Dublin. You can take the train from Limerick to Killarney via Mallow. Or you can take the bus, which is probably a faster option.

It seems that in many (all?) countries, you need a special type of
driver's license if you rent an especially large vehicle.

Driving license rules are harmonized across the EU, and most other European countries follow the EU standard. According to them a regular car license (class B) allows you to drive a vehicle with up to 9 seats (including the driver's seat) that doesn't weigh more than 3,500 kg.

Hi Jessica - one thought would be to take a look at the variety of Rabbie's Tours as an add on for segments of your trip. They can get you to the more difficult to reach areas. They provide transportation in a 16 person van, and will either book your accomodations, or you can do it yourself. We used them in England when we didn't want to rent a car and found it to be a great option for us. They allow one checked type luggage and one carry on.

The Irish bus service is an option provided your elderly parents are comfortable with the idea: https://www.buseireann.ie/.

I have visited Ireland five times. I have taken the bus all over Ireland from County Donegal in the far northwest to County Wicklow in the far southeast. The Irish bus service makes it to some of the most seemingly out-of-the-way towns. Once I picked up the bus in Aughrim, County Wicklow, which is a town of maybe 100 people. Bus drivers have no problem dropping people at places that are not official stops, but don't rely on their accommodating spirit either. I have also taken the bus from one end of Ireland to the other.

You're right about the train -- if you're not going to Dublin, it's not worth using.

I have rented a car twice in Ireland. It takes getting used to driving on the other side of the road. I would recommend against a car rental. However, if you want to look into it, I used Dan Dooley, which is now under the Enterprise name.

I would recommend flying into Shannon if you're going to spend a lot of time in the Killarney/Dingle/Kerry area. Shannon is closer than Galway. However, if a ticket to Galway is cheaper, than it's definitely worth seeing that beautiful town. Galway is among the most beautiful towns I have visited in Ireland.

One option to be aware of is that there are two flights per day on RyanAir between Dublin and the Kerry airport near Killarney, including one departing Dublin airport in the morning at around 9:00 AM as I recall. If your arrival time from the US is early enough you could jump on one of those and thus proceed to the Killarney area immediately upon arrival.
Though most here would advise against staying in Killarney town itself, in your particular case it may be your best option as a base in order to take advantage of the multitude of day trips and tours on offer there. You'd be able to explore both Dingle and the Ring of Kerry without having to worry about the cumbersome logistics of having to rent a car, though if the spirit moved you there are rental car outlets at the Kerry airport itself. Once you've shed your luggage you'd be able to rent a more reasonably sized vehicle for independent explorations of the peninsula ... maybe to include the very pretty Beara peninsula just to the south.
Coordinating the movement of a relatively large group with their luggage is going to take some planning in order to ensure a comfortable and stress-free trip. Taking advantage of the Irish public transportation system (such as it is) to get your group to the major cities and then booking day trips from there is probably your best option.

I like Robert's idea of basing yourselves in Killarney. It's popular for a reason: convenience. Once there you could rent the equivalent of a minivan and easily drive the Ring of Kerry, explore Killarney National Park and Dingle. And you don't need a special driver's license. I've seen plenty of minivans on the ROK, KNP and in Dingle and with the exception of the narrowest residential streets you should be fine. Even in a small sedan you would have to pull into a passing spot on the one lane roads. If you were to keep the van to transport the crew and bags to another city consider renting a van with a roof rack and car top carrier like a large Thule or Yakima. Just be aware of any height limitations.