14 Day Itinerary

In mid to late October you'll be dealing with much shorter days than in the summertime, and the likelihood of some wet weather means that you should have a "plan B" for days that involve any outdoor activities.
Powerscourt is always impressive but the gardens will be going to sleep by October. Glendalough is always a treat.
The Passage East ferry is great fun - you'll enjoy that.
Your day 8 is ambitious but not overly so. Traffic should flow smoothly since it won't be high season and you won't be dealing with all of the tour buses that can clog up the works.
The ferry across the Shannon you speak of is at Tarbert ... you'd use it on your drive from Dingle to Doolin. Doesn't save much time unless you want to take the scenic coastal route via Kilrush and Kilkee to get to the cliffs and Doolin. The drive is quite pretty on a sunny day, and there's a cliff walk at Kilkee that we particularly enjoy. If the weather turns sour however you're probably better off taking the inland route via Limerick.
Suggest taking the scenic loop drive from Galway, up thru Clifden (and the Sky road west of there), down thru the National Park and Kylemore Abbey on your way to Cong and Ashford castle. Would be a chance to see the best of Connemara - for our money the prettiest place in Ireland.
Your proposed trip out to Inishmore will depend on the weather - the ferry is sea state dependent and won't run if things get too hairy. You wouldn't want to be on the boat then anyway. Check the forecast the day before to confirm that it'll be a reasonably sunny day. The island itself is beautiful, it's the getting there and back that might be the issue.

I really appreciate these suggestions. Our "rainy day" back up plan is to visit as many pubs & listen to as much trad music as we can!! LOL! I looked into visiting the Village of Adare on Day 14 on the way to our final B&B in Shannon. I think it may be a good alternative from visiting Bunratty, which to me seems too "touristy".

Day 8 can be done. It will be a long day and of necessity you will have to trim or skip great stuff.....but is doable and fun. Skip Day 7. Blarney is on Rick Steves top ten tourist traps of EUROPE for a reason.....it's dreadful. Could think of literally hundreds of better things to do that connect to real Irish culture and history. Would urge using that time to expand other parts of your trip for a more in depth experience. As mentioned Newgrange is SO worth a visit.....or when on Dingle take a day trip out to the incredible, moving and stunning Blasket Islands. Worth every effort, or penny and investment in time. Or if you like scenery when near the tourist overrun Cliffs if Moher (beautiful but sadly often beyond clogged) consider going out to the wild stunning and prettier Cliffs of Kilkee !

Anyway a busy but doable trip. Hope you have a fantastic trip. Oh a hint.....when confirming a trad night at a local pub ...confirm its a full trad night. We were stunned when a local trad night started w 3-4 songs then announced they were doing a salute to the "great music of Prince" on tin whistle !!!!! Memorable, fun, and utterly bizzare but not trad. Then another pub in Kenmare...same thing..... a reel, a lament then incredibly a nights salute to.........Guns and Roses !!!!!!! Not kidding. Hysterical and the locals loved it but not exactly trad ! Have fun in wacky wonderful near perfect Ireland !!!!!

Thank you for the heads up re: Trad music! I tried to explain to my husband that Blarney is a trap, but he's really wants to kiss the stone. Me, no way!! I read and heard that the gardens are beautiful and unusual, including a poison garden, which creeps me out, but I'm curious. We're not planning on spending the entire day there, so it'll be fine. We're going back to Kinsale later that day and hike to and around St. Charles Fort.
We'll definitely look into Newgrange & the Cliffs of Kilkee as they've been mentioned 2 times already within this topic!! I really appreciate these suggestions!