(Incomplete, if you would like to help, please PM me.)
(Thanks to @Kuga for some tips)
Introduction to Momiji:
So you got your eyes on Momiji, eh? This is a fairly beginner guide to get you started on the character. For a more in-depth but outdated video go here and for a more advanced guide go...
I suppose i can offer some very bias tips: this is obvious but Rachel sort of struggles at long range she does have 2 good tools though 236P and 66K which still don't reach very far and are highly reactable. She struggles with traditional pressure (punching and kicking) but her PPT is amazing...
Take this with a ton of salt, but i don't think her 66T alone is very good. It does no damage, and only guarentees stuff on Hi-counter (3P). PPT is good for mixups and mindgames though.