I agree that Marcelo is a great dancer, but FYI much of what you describe above is part of the McKenzie SL choreography already, NOT an inspired-by-the-moment invention of Marcelo Gomes. Watch the PBS video and you'll see the same motions in Act II when Siegfried first spots the swans arriving etc., grabs his crossbow, 'sees' something wonderous/odd and precipitously leaves only to return to discover Odette. Ditto, the Act III BS variation with turns a la second (ie.with the leg extended) and then pounding the door after Green Monster Rothbart appears in a puff of smoke and slams them shut. The collapse to the floor in Act IV (though in the video its in response to the storm and corps swans leaping past in close proximity)is also seen in the video so I assume part of the original KM choreography.
But as you say, Marcelo Gomes has marvelous balance, and NO ONE at ABT does a sissone like he does. He is a great dancer (technically and artistically), a sensitive actor, and strong partner. And I am very glad he is at ABT and that you got to experience his many performances there.
I too am glad that he is at ABT and that I get to see him often!
I have no doubt you are right about the choreography--but some people, like Marcelo, seem to make it more meaningful and memorable for me. I have no doubt that David and Jose did the same choreography in the beginning of Act II, but they simply struck me as movements, whereas Marcelo made it make sense, for me at least.
I often have the same reaction listening to different musicians' versions of the same violin concerto, for example. The notes are all the same, but when some people play it, I'm like, "Ah! I've never noticed that passage before!"
Thank goodness for Marcelo!