How does my itinerary look ?

A few thoughts:
1. Personally, I would not waste time or money on the Guinness Storehouse. It is not a brewery tour, just basically a long buying opportunity for the same Guinness souvenirs you can buy all over Ireland. You could probably leave your bag at your hotel even if you can't check in that early.
2. It's going to be a long drive from Belfast to Blarney (roughly 6.5 hours), plus stops for lunch, gas, photo ops. Since you don't seem to have any plans to see Cork, why stay in the city? You could just as easily stay in Blarney or wherever you are going whale watching from. Traffic is crazy in Cork and if you don't want to see anything there, why go?
3. Have a Plan B for if you have bad weather on your Ring of Kerry day. When we went, that day turned out rainy and foggy and we could see nothing, so we ended up spending the day in Kenmare.
4. Not sure what you are planning in Dingle, but it really takes more than a driveby to see much. You might want to consider spending the night there. Otherwise, you will be driving from Killarney to Dingle, "seeing" Dingle, then driving to Limerick (about three hours). All you will really see is the inside of your car.
5. Rather than staying in Limerick, I would suggest taking the ferry across the River Shannon at Tarbert/Killimer. It will save you going around through Limerick. You could stay someplace like Lahinch or Liscannor, then see the Cliffs the next day.
6. There are farmhouse B&Bs all over Ireland that are working farms. We have stayed on sheep farms, cattle farms, and a farm where they trained jumping horses. You can get a directory of such B&Bs at the Tourist Information when you arrive, or from the Irish tourism website before you go.

Hi from Wisconsin,
The previous post is filled with good advise. I would skip the Ring of Kerry. There are a lot of reasons to skip it. The hedges are so high you need a step ladder on top of your car to see anything. It is perfect of buses. Go to Dingle and SLOW sown. Have a stay, so you can have a pint or two. Dingle is rough and rugged, filled with megalithic structures. Close by is Beara Peninsula if you must stay in your car and want to drive more.

Blarney Castle, better read about than visited. But you might need to do the kissing if relatives are going to hound you. I rate it a tourist trap.

The Brewery is best skipped. Kilmainham Gaol is worth every minute you stay in there. read about the 1798(?) rebellion before you visit. Cork ain't worth a minute. And Kinsale, south of Cork, is now over built.

In Dublin you didn't list Trinity College. It houses some of Irelands most famous items: The Irish Harp,, the Book of Kells, and under a large maple tree in the open center of the college is a sculpture by Henry Moore. Near by to the south of the college are some great squares and book stores.

Carick a reed bridge is worth a few minutes, the Giant's Causeway can suck up hours. It is beautiful. Make sure you walk as much of the cliff as is open.

wayne iNWI

I think the advice from both posts is sound. Having just come back from a month in Ireland, I think your itinerary is a bit ambitious. Try to play your first day in Dublin by ear as you will be jet lagged. With only twelve days in Ireland I wouldn't recommend trying to see everything. If you were to give anything up, I would let go of Belfast and the Giants Causeway and spend that extra time in the south and west. Blarney Castle is a tourist trap. Dingle is more than worth a side trip or an overnight. You could spend three days there easy, so definitely try to give it adequate time. Kenmare is a good place to base yourself if you are interested in the Ring of Kerry area. There are lots of great hikes near there. Killarney is a bigger touristy city. You can stay there if you like but if you wanted to avoid crowds and tourism, Kenmare is a decent option. I also agree with the suggestion to ferry to Killimer. Lehinch is a good place to base yourself, otherwise, Doolin or Ennis are other options. If you wanted to, another option would be to go from Dingle to Galway in the same day. It would be a full day but you could stop at the cliffs and drive through the Burren which is amazing.

Jennifer, I'm going to go against the grain and say go to the Guinness Storehouse! My husband and I did it our first day in Dublin and thought it kind of set the stage for our days there. After completing the self-guided tour, you get a "free" pint to enjoy while looking at a panoramic view of the city. We got skip-the-line advance tickets as the lines can get long. We did the whole thing in about an hour. Touristy, yes, and a bit overpriced, but a fun way to unwind after the flight and nothing too heavy to absorb (except for the Guinness, of course!)

Enjoy Ireland!

Grab a map or look at the island via a Google satellite image. IMHO driving from Belfast to Cork seems a waste of precious time. If you are heading to NI why not see more of it? The Titanic Museum in Belfast should be on you must see list. On Wednesday get an early start to visit the carrick a rede rope bridge and the Giants Causeway. Grab staples for a picnic lunch in Donegal and head for Galway. Spend the night in Galway, listen to some trad that evening and in the morning head for the stellar Dingle Peninsula, stopping to see the Cliffs of Moher enroute. Spend two nights in Dingle. Visit Killarney proper and do your climb on one day. Overnight in Dingle. A pint or two at Foxy Johns will soothe the aching muscles. Next day drive over to and explore the Gap of Dunloe. Hike it, drive it or take a traditional trap ride. Stunning locale. From there drive into Killarney to enjoy Killarney National Park's beauty. Maybe visit the Muckross House. Back to Dingle. Up early and out the door of your B and B to explore the Ring of Kerry. From the Ring of Kerry either head off to see the Rock of Cashel or depending on your stamina you could drive back to Dublin or overnight in Kilkenny then head back to Dublin from there the next morning. Agree Blarney Castle is a tourist trap. Spend more time merely enjoying the island's natural beauty.

Claudia and the others make a lot of sense. Consider it. I think you are wasting a lot of time and not using your routing wisely. Blarney Castle(tourist trap) and Cork(smaller version of Dublin and Belfast) don't compare to NI, Donegal and County Mayo. Not worth the trouble. I suggest you make the counter clockwise loop from Belfast hugging the coast when possible to end up in Dingle. Stop in beautiful Westport, if you are a hiker. Crough Patrick is considered by many to be the best mountain hike in Ireland. and take the magnificent backroads to Galway from there and then go through the Burren to the Cliffs stopping in Doolin for great music before getting to Dingle vis the Killimer to Tarbert ferry.
And why go all the way back to Dublin? Can't you fly to Paris from Shannon? Or save Paris for another trip and spend the rest of the time enjoying more of Ireland( What I would do). Why Limerick? Unless you have a compelling reason to go there Limerick is like going out of your way to stay in Cleveland. Once again stay on the coast.
I have been to Europe many times and the best advice I can give is not to try and do too much and use your time wisely. If you like Europe a lot you will go back. I really think you need to sit down with a map and logically make a route rather than jumping around so much.