I'd like to ask you and other knowledgable parties 2 more (for now) questions:
Since only 2 nights in Killarney will cause us to have to choose between Dingle Penninsula and the Ring of Kerry, would we be wise to change it to 3 nights instead so that we can do both? Are they similar or very different? (I guess that was a 2-part question)
The second question: Is Doolin near enough to Shannon to comfortably make an afternoon (3:15) flight?
Yeah if you want to tour both Dingle Penninsula and Ring of Kerry then 3 nights instead of 2 is the way to go.
Yes you can easily make Shannon from Doolin for a 3:15pm flight and you won't have to get up early and miss breakfast either. You will have plenty of time if you leave around 10:30 - 11am.
Very good advice from Mark on your questions. Killarney is a good spot for a base since it is so central to the southwest. Dingle town is about 1 to 1 1/2 hours from Killarney. Of course doing all of Dingle will take most of the day. The Ring of Kerry also takes most of the day, especially if you tack on the scenic Skellig Ring or Valentia Island. As for which one is better, Dingle gives you more bang for your buck, so to speak. The scenery and beauty just about floors you at every turn. The ROK has some excellent scenery but is a bit more subtle. If you were to choose just one I would suggest Dingle. But if you want to do both then three days would be good.
It is about a 1 1/2 hour drive from Doolin to Shannon Airport. You have plenty of time to catch your afternoon flight. Just be aware that international check-in is 2-3 hours prior to departure time. You also need time for car return, VAT refunds and any last-minute shopping at duty free.