I've worn my kilt several times in Dublin. Mostly at stag nights which Dublin is very popular due to the easy reach from mainland UK.
Also wore my kilt in Dublin for football match, Ireland v Scotland. You will find Ireland very receptive to kilt wearers as they are a celtic nation and they have the kilt as their national dress (although not tartan).
Dublin in particular is one of the most cosmopolitan cities in the world and tourism plays a major part in their economy so you will find that wearing your kilt their will be a very welcoming experience as it is in every country of the world that I have visited and worn my kilt in.
Wearing your kilt anywhere is always an adventure and a delight.
Julian