On a small side note, it's funny to me that a bunch of ex-airlines have had their names resurrected. Consider Midway, Braniff (at least 3 times), Pan Am.... No one has considered resurrecting Eastern. Damn shame too...what a fine airline.
As for the route structure, it seems like the european routes were not a good idea--but on the other hand, they had very few of them, so you can't say that it brought down the airline (but I can't help but wonder how much good it was to have been maintaining a few DC-10's for a Tristar carrier.)
I think the LatAm routes fit well with Eastern--they were able to bring passengers from other parts of the country and connect them onto flights going to Latin America in a way that I suspect Braniff was never able to do. The routes had to have been profitable in some way...otherwise they couldn't have sold them to American. (Perhaps some of this board will disagree, but as a rule, airlines on the verge of bankruptcy first sell their most profitable routes. Pan Am first sold their pacific routes to UAL, then their euro routes to Delta...Eastern sold their LatAm routes to American.)