Dia duit, Ruadhan
Welcome to Susan's. I'm sure you will find many here who have walked a similar path as you have/are/will (though I'm walking the opposite way myself - MtF).
While I am Irish (decent), I unfortunately do not know a word of Gaelic. I had to look up the greeting. I do love the language and love to hear it, though my linguistic skills leave a great deal to be desired and I can't hold on to a new word, phrase, number, etc in any language for more than a few seconds.

Well, I hope you enjoy your stay here.
Deanna