I haven't been to Dingle for about 15 years but I'd suggest sacking Dublin altogether and going straight to the west coast. Dingle was lovely when we went (twice in one holiday as there was so much to see) and Inch Strand was like a piece of heaven on earth (not small either Spaw - a long, wide white sand beach); one of the best places in the world.

As for the driving I really wouldn't worry. Unless you're a really bad driver then the roads aren't so much of a problem. My stepfather helped build the M50 so that should be all right, and the smaller roads are full of interesting sights and views etc.