I research the Irish Family History Foundation's database. It contains 12,000,000 surviving rcds for abt 65% of Irish counties. Rcds are increasingly sparse B4 1840, rare B4 1800.
Note 1 - Without a KNOWN county, the chance of an ancestor's rcds NOT being in this database is AT LEAST 35%.
Note 2 - Only 1/2 of Co. Cork's rcds are in this database.
Note 3 - The RC church kept control over most parish rcds from Tipperary (north). These are ONLY available thru the Tipperary Family History Research center at a substantial fee (regardless of outcome).
Croagh is a townland name which occurs in several places: Co. Cork (west), Donegal, Limerick, and Donegal.
Frosses is a townland name in Co. Antrim.
Inver is a townland name in Co. Mayo, Fermangh and Antrim.
Dunkineely is a townland name in Co. Donegal. So is Bruckless.
Ballybrillaghan is likely a corruption of the townland name Ballybricken. This corrected name occurs six times in Ireland, mostly in Co. Limerick.
Since you have so many relations, will let you visit the database and search for them. Note - Co. Donegal and Derry rcds aren't in the database yet. Suggest you wait until they are before pursuing a detailed search.
Google the Foundation's name to lead you to this database. Register, opt to be notified as rcds are added and browse. Pls post your search results to my genforum msg.