I was in Ireland in September, drove all over the country on the wrong side of the road in a manual shift Kia. Didn't take that long to get used to driving on the wrong side of the road.
Just be carerful on the east coast. The roads are very narrow and some of the country roads are only wide enough for 1 car. You could come around a blind corner and run smack into a tractor, and there's plenty of blind corners. Some of the roads are simply thrilling, but also dangerous. Also, be aware of the tour buses on the coast and in Kilarney National Park. They will smash you into the rocks.
Yes. Dublin has it's traffic, but I didn't think it was quite as bad as some major cities in the US. Also, I stayed at the Renaissance on St. Stevens Green. It's really in the perfect location for seeing sights in Dublin. It's a very nice place, but I think pretty pricey. It's in a beautiful old building that's been re-modeled recently.