Commuting to/fr Ireland takes its toll. I had to virtually do it for 2 months due to family issues - it was only possible because of generous scheduling and creative trading. Getting into Ireland is the hardest because you have one maybe 2 flights out of multiple US airports so you have to pick which one will most likely get you over there. Having the Aer Lingus bennies makes it way less complicated, that makes 3 flights a day out of JFK to DUB. (2 EI 1 DL)
Heading out of Dublin is easier since there are about 10 flights that run out of there starting at 8 am and spaced out with an hour or two between each flight so you can work the line. I have always gotten a seat on the days I travelled but it takes a lot out of you (16 hrs door to door for me to get to Boston).If lucky you would be in Ireland for 2 full days out of 4.

Since you wife's father works there - why not move there, get you EASA license and get on with Shamrock. Then you will be home every night....way better QOL!!!!