--Elros asked Elrond to watch over his family, even when they become stubborn and the foolishness of men overtakes them

--Elrond always kept watch over on Elros's descendants. If they were ever in a situation that was dire, Elrond would mysteriously be there

--Only if they would accept his help, Elrond is a gentleman and would never force his help on anybody, even Elros couldn't ask that of him

--Elros blessed those of his descendants and anyone who would remain "the faithful", this is why they were able to escape and knew when to do so

--Elrond has called Aragorn by his twin's name, Aragorn tall stature does not help