Ireland itinerary help

You have ten days, which is reasonable for the destinations in Ireland on your list. If you wanted to see London, I would say fly to London from Dublin on Day 7 and then fly home to the US from London (even though your out-of-London flight might involve a change of planes in Ireland, depending whether you fly Aer Lingus or another carrier).

Ireland has trains and buses, of course. The service is not always frequent and the routes are not greatly comprehensive, but the major points of interest you've listed are served. Here's Dingle public transport information
https://www.dingle-peninsula.ie/home/travel-information/public-transport.html

Amanda

One thing to know is that there is a bus now in the Iveragh/Dingle area that you may not see when you do research. It's called LOCAL LINK. This may be very helpful to not have to depend on Bus Eireann to get to Dingle!

Susan
Expat living in Waterville/Skellig Coast

I think that you will find yourselves with significant travel times on parts of your trip. Dublin, Giants Causeway, Galway, are easy on Public transport. The Cliffs of Moher a little harder and a day tour from Galway just might be the way to go.

Galway to Dingle is a longer trip on Public transport. I’ve tried every way I could to find a public transit option that didn’t add at least 2 hours to the trip. I haven’t succeeded yet.

My current compromise is a rental car from Galway to Dingle and then back to Galway. We would finish the trip back on public transportation. Cost for a 3 day rental from Galway for a car with an automatic transmission is 92 euros.