After rewatching it a few times, it does look like this battle is more symbolic of the role of Xemnas in ruining the friendship of Roxas etc and thus forced the battle we saw in KH2. I agree with you about the songs, whilst I do prefer this to Chikai, which I still cannot warm too, it doesn't have the same affect Simple and Clean or Sanctuary had. That being said, the trailer seemed well edited and perhaps flowing normally, the song might change my mind.
The eye debate is an interesting one as it propels many theories and could play credit to a few 'leaks'. I'm in the air on this one, whilst the silver eyes did look cool, I like the iconic yellow eyes. My issue is, I want the yellow eyes to remain a Xehanort characteristic and having him a puppet or under the influence of someone else, cough MoM cough, just seems too cliche.