Yeah the roller disco angle would fit perfectly. It's her outlet. That angle alone would make her an outcast of sorts. Her and her friends are quirky but their day to day lives are filled with the redundant boredom of "normalcy". She wants more, she wants to find her place, she wants to be out from under the thumb and scrutiny of her parents (take your pick: hard drinking father/mother, resentful father/mother, step-parents, etc.)
Best of all I think it will provide a lot of what Logan did for the genre. Take the genre out of it's comfort zone but not so far that it's no longer a comicbook movie....if that makes sense.
She's conflicted about her powers of course--it makes her special, but still a freak. She comes out to her friend(s) unsure of how they'll take it. Their response is mixed--distrust: is she using her powers during the competition--is her being a mutant an unfair advantage, is she dangerous. nah, she's still "Jenny from the block". A sequence where she accidentally hurts one of her friends would bring the "potentially dangerous mutant angle" home to the audience. Yet they coud still sympathize with the character's plight.
Of course you'll have a few set pieces where she discovers her powers, uses her powers and ultimately decides stopping a crime by one of her closest friends (relative? younger sibling? etc.) is more important than the dance contest. She thwarts the crime in her dance costume--Dazzler is born. This could play out a number of ways of course.
Feel free to flesh it out some more. I think the gist is obvious and I would understand if some felt it was derivative. But I think for a Dazzler movie and the natural/organic progression of the MCU (with mutants) it simply fits like a glove.
What do you think of Jude Demorest or similar look as Alison Blaire? I don't want the girl next door look, something more ....seasoned...mature? I can't find the word to describe the look. It's the look Travolta had....street smart....it said pretty Italian boy from Brooklyn/Queens.