Greetings from Ireland.
ST. PATRICKS DAY IN DINGLE - A MUST-SEE
My immediate recommendation is to have St. Patricks Day in Dingle. Getting there is actually easy from Dublin on public transport. Simply train/bus from Dublin to Tralee and then public bus to Dingle. Its a long journey (aren't all the best ones) but very straightforward. They have the earliest parade in the world at 6am! So much fun, marching in the darkness with the locals, virtually no tourists (they are mostly all in Dublin dressed in green and getting crushed). Then at mid-day they have a great parade, with some military, sports teams, children groups, local arts and community floats and the local fife band. There's so much emphasis on the cultural value of St. Patricks day, and then afterwards people can go to pubs, theres 56 or so in the village, but its not a wild chaotic scene, though it is great fun!
ST. PATRICKS DAY IN DUBLIN - IF PLANNED RIGHT, CAN BE GREAT FUN.
March is a great time of year to come, don't be put off by your perceived wildness of St. Patricks Day, its really only like that in the centre of Dublin, and mostly because of tourists and Irish teenagers, who have had too much to drink. The rest of the country is quite fun on St. Patricks day, Dublin is too, but you'll need the advice of a local to make sure you see the right spots and wonderful cultural activities on offer in Dublin during the St. Patricks day festival. A dear friend of mine is an organiser of the festival in Dublin and they go to great lengths to ensure there are tons of wonderful cultural offerings to celebrate out patron saint sand our national heritage.
But you're right, the temple bar area and a lot of the city-centre on St. Patricks Day and the night before, would be perceived as absolutely drunken chaos by a lot of people, though other visitors would of course love it.
TRAINS IN IRELAND.
The system is not really puzzling at all, its just very limited. You can get to Waterford, Kilkenny, Belfast, Cork, Killarney, Tralee, Limerick, Galway etc ... most of the major population centres in the Republic. And from there take day trips, or public bus to various sights.
If not booked online they can be very expensive, so go to www.irishrail.ie before hand.
The first class carriages are nice and not expensive to upgrade on, but the journeys are so short, it might be worth it for you. Personally I always do regardless, but thats just me.
Any questions just respond here or send me a message.
Le meas/with respect
Stephen McPhilemy
Rick Steves Ireland Tour-Guide
Derry, Dingle & Dublin.