I would say with the correct marketing in the likes of Edinburgh, Glasgow, Vilinus, and seasonally in Helsinki, Aer Lingus could get the load factors up on routes like New York, Chicago and else where state side.
Northern Counties, you are right on this one, though to be fair to EI they saw a 50% increase in transfer passengers going to US at Dublin over the summer months, maybe in some part due to Aer Lingus Regional and I note that in NewYork there was quite a bit of marketing of Dublin as a connection point. This increase in transfer passengers may be a reason why fortunes at the airline have been on the up and up this year!
EI-BUD