Things I wish we'd got in the 10Dance movie (that was in the manga):
Suzuki's sexy accented English. That was one thing I found absolutely hilarious in the manga, that whenever Suzuki started speaking English, everyone around him thought that either he was trying to pick them up, or he was faking it to sound sexy. Truth was that Suzuki picked up his English from his Cuban grandmother, whose English had that added sweetness to it.
Suzuki's 9 half-sisters. Come on, we have all seen the Suzuki genes, can you imagine how drop dead gorgeous his sisters would be? Also, the sister training to be a doctor seemed very cool. And growing up with 9 sisters meant that Suzuki was very well-versed in girl talk.
I know they made movie!Sugiki a loner because it fitted into the dynamics that they were trying to build there, but in the manga, Sugiki actually has friends, and his closest friend is very gay and was very much in love with Sugiki to the point where he got pissed whenever Sugiki started speaking about his feelings for Suzuki which would have been different if he was a "woman." So yes, would have loved to see Ernie in the movie, even for a moment.
Liana clocking that both of the men she had been dating (and the one she married) were both gay. Giulio totally has the hots for Sugiki in a /coughcough/ heated rivalry sort of way, and when Sugiki tells her that his reason for existing now is because he has found his worthy rival (Suzuki), it totally has her rolling her eyes at him, and lamenting the fact that Giulio wanted to hear these words from Sugiki all his life, but he never got to.
Fusako being married to a guy who is the biggest Sugiki fan, to the point where he doesn't mind the fact that his wife spends all her time with him. Pretty sure he gets off to that, too.
Suzuki dropping out of the pro scene for a while because he insulted a judge (pretty sure he punched him), and then him going underground and returning with a bona fide pro certification and then sweeping all the national Latin championships.
Also, it was pretty much obvious in the movie without having to spell it out, but in the manga, it's hilarious how everyone refers to Suzuki as "walking sex" (which, valid) or Mr. Sexy, because that's the first thing they see about him. He's the living personification of the "everyone in this room wants me carnally" meme, and he's not always aware of it, which is very cute.
Obviously, tonally the two pieces of media are very different, but I feel like a little depth into their characters (like why Suzuki was exclusively dancing only for the nationals and did not apply for the international competitions—it was so that he could send home the championship money, or how Sugiki has an entire network of people in the UK, where he grew up, and how he blends right in whenever he goes back, and even his relationship with Martha, which is more interesting than the two lines she utters in the movie), would have added some much needed complexity to the already nuanced reading of the characters.