I think Final Destination, Smashville, and Omega stages are Mario's best stages in my opinions.
: Against these Rosalina, I've avoid Delfino Plaza and Halberd because of low ceiling and she can get early kills with up-airs, and juggle me with platforms arounds. Same with Battlefield and Dreamland, but alittle because with platforms, they can help her more than Mario. I stick with Smallville, FD, and Omega stages to limit her juggles and early kills.
: Same as Rosalina, but if you go to Lylat Cruise and Duck Hunt stage, then it will limit her options and you can live longer.
: I avoid Battlefield and Dreamland because of their range and they can use it to juggle and pressure you when you're on platforms.
: Any stage with platforms are good for you and bad for him because his crappy air game and jump height can be used against him.
: Battlefield and Dreamland because they help you alittle more and he'll have less space to run around.
: Battlefield and Dreamland seems ok so she don't camp you with needles.
: Up throws can help them get maybe early kills 140% at least(along with rage) on platforms, nothing more.
: Battlefield and Dreamland, she can use her SH n-airs for pressure on platforms and her up-air for alittle more air pressure. Autoreticle for pressure and zoning when you're on top of platforms with Mario. If you're facing her with Lightweight on Delfino Plaza, Halberb, Battlefield, and Dreamland, she can use Lightweight over at anytime when she's on platforms and can get early kills out of her up-airs because of low ceiling.
I don't have anything so that's pretty much it.