Hi,
I'm familiar with the area, so let me know if I can help. You've got the correct church etc. If you are searching for marriages, baptisms etc (in the national library in Dublin) or elsewhere, make sure that you search for records under Addergoole and Liskeevy (Liskeevey), as this was the name of the parish pre 1900 (or thereabouts).
The boundaries of the parish might have been redrawn at some stage (I could be wrong here!). Nowadays, the parish of Milltown takes in the Milltown area (St Josephs church), and theres another church in Ballyglass (about 3.5 miles west/north west of Milltown. Most of the Ballyglass half of the parish live in Co. Mayo, whereas the Milltown half is based in Co Galway - this is very unusual as far as I'm aware. There is a graveyard in Ballyglass, very close to the church.
In the Milltown side of the parish, there are graveyards in Liskeevy, Kilclooney and Addergoole.
As suggested above, I'm not entirely sure if the modern parish of Milltown has precisely the same boundaries as the "old" parish of Addergoole and Liskeevy.
Another potential distractor is that there is a parish/district somewhere in Mayo (to the north of the county as far as I'm aware) also called Addergoole, so dont fall into that trap.
Milltown is a lovely little place - and for most of the past decade has been the tidiest town in Co Galway.
There are still Farraghers in the parish, not so sure about Dalys, though there are Dalys in the neighbouring parish of Kilconly. Both names are reasonably common throughout the county.
Best of luck with the next phase of the search!