Dazzler: The Musical... still a nope from me.
Dazzler: The Movie with an occasional performance in a concert setting, that I'm down with. A film with a Dazzler soundtrack as a marketing ploy, that's something I'd be down for as well.
I don't need to see the character breaking into song... fighting a baddie... getting ready for a date... whatever...
She's a mutant, she's a member (part-time, occasional, reserve) of the X-men, she's a singer... one element/trait/etc. doesn't supersede everything else.