First time in Ireland - 7 nights - tentative itinerary

I'm not sure that Killarney offers an "authentic" Irish experience. It's certainly typical for American tourists to go there. You don't indicate what time of year you're traveling, nor anything else about what your interests are. I assume you will rent a car, although you haven't explicitly said so. Why have you chosen these locations? For such a short trip, I suggest dropping one of these locations (likely Cork). I would also consider taking the train between Dublin and Killarney and either renting a car locally or using organized tours, particularly for the Ring of Kerry. The driver (especially one who is not experienced driving on the left, which may not be you) doesn't get to enjoy the scenery fully. There is a lot to see and do in and around Killarney and Dingle, and you'll have to choose very carefully if you only give yourself one full day there.

Thank you for your response.
We will be traveling in mid October and the plan is to rent a vehicle the morning we depart Dublin after our 3 night stay and keep it during our entire itinerary up until returning it at the airport on the last day. I do have experience driving on the left side of the road, I've driven in the Caribbean islands multiple times, which happen to have lots of roundabouts, and I do enjoy driving. The reason we chose Killarney area as the first base is that it's close to the Dingle peninsula and the Ring of Kerry so that would allow us exploring that area first, then we chose Cork/Kinsale as a second base in order to explore the Southern part of the island as well, and its picturesque towns, and enjoy seafood. When I said an authentic Irish experience, I'm talking about going to local pubs, listen to live music, enjoy the environment, enjoy the Irish hospitality and also enjoy nature, we don't care much about being in a city with lots of activities, with the exception of Dublin that packs so much. We're not looking to hang out with other tourists, in fact, we prefer to do our own thing, we are not tour people, we just create and follow our own itineraries, staying flexible along the way if we hear or find out about something new. I understand for some activities, a tour is preferable, so for now, we just want to nail down the itinerary. We're intentionally avoiding going to Galway since it would probably be a bit much travel time.
Thanks.

I also should probably say too that I have sorted accommodations in those places almost at no cost, due to my credit card and hotel reward programs perks and benefits. That was the main driver, so now I'm trying to make it work. If there's a better alternative, I would appreciate any suggestions. We're trying to minimize 1 night stays, so it's either 2 nights in 2 places, or the 4 nights in one place, however this would create longer commute times between places.
Thanks

I'm in the minority camp, but our first trip to Ireland was ALL one night stays - sort of like a sampler of chocolates. Our upcoming sixth trip is 3 weeks with mostly two night stays. All of our trips have been late April to early June, mainly to avoid the crowds, although it's a little harder to find great music on the shoulder season. We've never taken an organized tour except your basic 1 hour guided tour of Newgrange, Dublin Castle, etc.

Maybe move Kinsale/Cork to Killkenny? Maybe one less night in Dublin? Killarney is pretty touristy, although October should be better.

The good news is that over all our trips, we've never been disappointed with where we stayed or what we decided to do. The biggest planning error is discovering the weekly music session in a given town was yesterday. I now plan trips by looking at music first, then location.

Thank you for your observations.
We thought about those music concerts too, unfortunately nothing that appeals to us have showings during our visit :(
I think we'll stay in the Killarney area for 3 nights so that we can enjoy more of nature in that side of the island and have a more relaxed vacation (I remember doing quite a few of those 1 night stays early in our travels, now I only consider those if absolutely necessary); our last night will be nearby the Cork area in a nice resort nestled in the woodlands.
Like you said, I don't think we'll be disappointed, Ireland is long overdue for us and October should be a wonderful time to visit.
Thank you!

-3 days in Dublin makes sense. The hop on hop off bus is a great way to get around. But it’s a very walkable city, too.
-instead of staying in Killarney, consider staying in Kenmare. It’s just 30 minutes south, it’s much smaller, calmer with lots of shops & restaurants & it’s really lovely & very walkable. It has a large, very easy public parking area & you can leave your car there for a few days even. It would add 30 minutes to your drive to Dingle. There is a bus stop in town to take you to Killarney to visit. Also, if you wanted to drive the Beara peninsula, it’s far less crowded & very beautiful. It’s smaller than the Ring of Kerry so might fit you time schedule better. I’ve driven both & I thought the Beara Penninsula was just as beautiful as “ The Ring”.
-Never been to Kinsale & hope to go this October. Have a blast.

Thank you for your message.
Yes, I'll look into your suggestion of the Beara peninsula, Rick Steves mentions it as a great altenative. I've also seen good commentaries for the hop-on, hop-off bus in Dublin from multiple sources... even though it's something we usually don't take, we'll consider it... Actually, we won't be staying in Killarney, but nearby in a hotel by Fossa facing one of the lakes... Kenmare is definitely in our list, since we will be renting a car once we leave Dublin, it'll be easier to visit.
I appreciate your feeback... Thanks again.

Re: Kenmare. This is not a place to visit. This is a convenient place to stay for visiting the Ring of Kerry. It is very touristic and offers nothing of substance.