CC being made into a choreographer is an incredibly minor change. In the show, he's the songwriter and is there with them every step of the way. It's easily believable that CC might have helped choroegraph the group in their talent show days. He could still be the songwriter as well. It adds a dimension to the character and gives Condon an excuse to add CC to a dance number or two. It's a good idea -- it makes CC a slightly more interesting and dynamic character than he is in the stage version. A nice, but hardly significant change.
Geffen has always owned the film rights to the show as well as a bunch of other subsidiary rights. He's long been very protective of the property, having refused many overtures for a film version over the years. He and Dreamworks are the producers, so while Condon has a free hand to a point, Geffen can always step in if he doesn't care for the direction Condon is taking the project in (doubtful that'll happen, though).
And I'm very happy he didn't allow the concert to be filmed. While it was valuable to have a full account of the score (which is why he allowed a CD), it lacked polish and was too often poorly sung (Hedley was a disaster -- Lorrell's music was way out of her range and she was painfully flat throughout "Ain't No Party"; Audra had way too much vibrato for Deena; and Lillias choked on "And I Am Telling You I'm Not Going" -- probably the worst rendition I've ever heard from her).
"What a story........ everything but the bloodhounds snappin' at her rear end." -- Birdie
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"The Devil Be Hittin' Me" -- Whitney