First of all, thank you all so much for the responses! But it would appear I need to clarify...
When I listed Dingle, Trim, etc., I intended them to be examples of what I meant by quaint, and with the exception of Kinsale, not accessible by rail. I would rather NOT be in a modern suburb/housing track. By quaint I meant a traditional Irish village atmosphere with unpretentious places to eat and pubs, hopefully with music. I've stayed in a number of them but none close to Dublin. In looking at the rail maps, it's difficult to determine where each community with a rail stop lies in that spectrum.
The desire for rail access to Dublin is two-fold. First, it would be nice that any visitors flying in could have convenient access to both Dublin, and the airport without hiring a car or requiring a shuttle service of me. And second, as I stated I really enjoy Dublin and with the length of time I'm considering, I would like the ability to travel in without driving. Driving to a station could be acceptable, but walking to the rail would be much preferred. Asking a lot, I know!
I have a little problem hiring a car and in fact, will need to from time to time no doubt, but I'd rather not drive into Dublin. It does add expense to a lengthy stay, but maybe not as much as I might think. Another thing on the list to look into!
I have driven all around Ireland, following Rick Steves 3-week car tour. Kilkenny, Waterford, Kenmare, Westport, the Connemara, Derry, Portrush, and the four I previously mentioned. I would love to stay in any one of the places, but they're so distant from Dublin, except maybe Trim or Enniskerry if I succumb to relying on a car.
I've never stayed in the Midlands however. Any thoughts? Mullingar - was to be home to Fleadh Cheoil na hÉireann 2021 that I wanted to attend, but Covid-19 cancelled it!
Skerries is looking interesting. But I am open to other ideas for places.
Again, thank you so much for any input!