Thanks for this info, it's been a damn big help. In playing a few matches, I'm also realizing that you shouldn't (or just can't) use her iceball in projectile wars, but she definitely has some really interesting tools (like an honest to god overhead). I still need a lot more practice and experience because I still freeze up in situations, do YOLO parabellums, and don't use her parries as much as I should.
But it has been enjoyable, which is something I couldn't really say the last several attempts I had in trying to get into this game over the years.
I still struggle to use her hailstorm effectively. I can use it for mild pressure, catch people by surprise (since it is slightly delayed) and for some extra damage on stun combos. But I can't shake the feeling I am missing something there.
I also keep forgetting she has a mid-air projectile of sorts + extra jump in her j.cr.mk.
Parries are cool, but aside from AA I mostly reserve them for wakeup. First two wakeups are recon for me, seeing what the opponent does. If they didn't throw, I will parry them the third time.
At neutral or close range I don't use frost touch at all, and use her v-skill instead. It has a long startup (15 frames, while the actual counter only connects at frame 8-16), but it catches all hit levels.
(Part of me wishes they would make her ex.frost touch catch all hit levels as well, but that would make it way too powerful.)
Edit: Another thing I just remembered: all ex vanity steps have projectile invincibility. Light (lk+mk) and medium (lk+hk) > punch are good, but require strict timing. The heavy (mk+hk) one seems to be the best, since it it has 55 frames of projectile invincibility and if you land in front of your opponent you can combo into lp>mp>hp>parabellum from it.