We have opposite views on the subject and I'm probably not the person to help you.I've done this for years and you are discarding my advice ... but here is my last comment:
Talking about pulling John's IRE records is pie in the sky b/c you can't make the jump to a county/townland.
Who cares how long he lived with them - he lived with them.Who cares how he is related?He arrived w/in a few years of them and is in their household; he is related.Hugh is your biggest breakthrough.With the common given names you have collected, you can't make the jump back to IRE, so forget about looking for a John among the 100s of possibilities until you can narrow down to a townland.
You finally have a unique, traceable name living with "your" Hassetts?Make the "jump" back to IRE and pull those Irish church records.Imagine this scenario - you pull Hugh's cert in WMTH; it gives his mother's maiden name and you confirm that they are only in WMTH as overseers, BUT you see the marriage in another county w/a townland --- all new leads.
Also, find Hugh's NY death cert and obit.PHONE the cemeteries with all your Hasset's dates of death and get lists of who/how many are buried together.
My advice is to focus on the unique -- you'll spend endless yrs looking at everyone named the same John/Pat, etc.