I don't see Ballykissangle anywhere.

I think it's quite obvious, Mary will never marry Tom because she won't "marry down". And Tom won't marry her because neither will he.

Wasn't Violet the one who said something about Mr Pamoush's death, one 'did not have the bad graces to die in someone else's house'. I suppose the logical progression was one was supposed to die cleanly and without fuss in their own house.