I agree to all that's been said above, although I never really made the connection with Legolas bringing Arwen to the coronation, I just figured Legolas was with the Mirkwood Confederacy and Arwen and Elrond were in the Rivendell Confederacy
Legolas's senses are definitely more finely attuned so he is in a big way the one who makes sure there are no buckets of water propped on top of any doors to saturate the Fellowship, lol. Also, because he is so quite I expect he watches them closely and has a very good judge of their characters, so when they get a little sidetracked and lost and confused Legolas is there to bring them back to themselves.
And I believe, but don't take my words for gospel, but I think Legolas first met Aragorn when Aragorn was a child in Rivendell, and Legolas was a regular in Rivendell and Aragorn doubtless journeyed to Mirkwood once he was old enough. Correct me if I'm wrong though.