I don't remember/recall the teaser, but I didn't care for it as much because of it coming after what I thought was a super effective conclusion that puts distance between the two of them.
With you on the musical number, the subversion isn't really there, so it's just Silverman singing and helping the film transition back to Slaughter Race. But at that point I think the movie really has a grasp of what it wants to explore, so it just feels jarring. The King Kong part is also very on the nose, and kind of overdone. I think it lays the groundwork enough for it to be believable in context, but it's very obvious set up that feels heavy handed (like Ralph, his hands are big). I did like the princesses though, and think they thread Vanellope in with them really well, but mostly I just love all of their casual outfits and the sayings on their shirts. From what I did see of the full on trailers before things, I did go in with some hesitation, and it wasn't unwarranted through the first 30 minutes or so because it gets so terribly memey and referencey and basically just has the two go through the Frisco of Silicon Valley's opening credits, which is fun, but kind of dull.
Turns a little bit of a corner when that gets used more as dressing and we get to Disney proper as it lets the movie finally just have fun, and at that point I'd have been fine with it just being a whole big crossover film because it wasn't emotionally hitting anywhere close to the first and the driving story that made the character work so effective in the original was hardly as compelling. So whatever, just cut loose, do some Disney stuff, and and let me enjoy that in a different art style. But I'm glad about where it goes. As it starts to reveal itself and focuses on that disintegration and restructuring of the relationship between Ralph and Vanellope it gets surprisingly mature for a film that, for a lot of the early run time, felt like an unnecessary sequel. That moment where she hugs him and tells him she loves him, it's so sweet and hits in the way it should. People likely won't like the comparison, and I know I'm the only one who holds it in such high regard, but the ending of Superbad is so wonderful to me because you see that growing distance even though you have also had that reconciliation. It's just so real, and continues to be one of my favorite endings to anything I've seen, so I was glad to see WiR2 not only echo that, but also commit to the separation. Until the threequel, I guess.
Also, not sure if it's just Disney convention and all the talk from the princesses, but this could have strayed in to some real yucky territory with the Ralph/Vanellope/Shank relationship, because it really felt framed like it should have been a romantic plot, but they don't lean super hard in to it and things mostly fall platonic, which is obviously good because Vanellope is most definitely a child. Leave that gross shit to the fan art communities. Though I think the idea that is probed, if applied in another film to different characters in a romantic context would also be super compelling because that idea they eventually hit on is just so strong.
EDIT: I think you were right about the 3-D as well, 1SO, though I only had the 2-D option since my theater only had a single 3-D screening all day. There are definitely parts where things would pop out, and I am always down with having things hurtle towards my face.
EDIT 2: Loved the Jason Mantzoukas cameo as well.