CT, re SoM: Personally, I'd see Suiko3 characters as charging their spells immediately - as soon as you finish entering commands, the mages get the "casting" look. So I don't see Jane letting them "start" make much sense. Admittedly, I'd see your point for, say, FFT Dancer/Bard... no matter how fast Dancer is, her dances go off at a set charge pace and Dancer's own turns are kind of irrelevant. Anyway, for Suiko3 I'd see Jane as just making all spells go now - a character casting a huge charge time spell is basically the same as a slow WAACF character.
Re Repede: Well, I'd see Repede's invincibility as going off very very fast, but still losing to initiative, so yeah, he burns except maybe against Middle. Against Middle's fastest... he has to outrace XS3 Jr., LoD Meru, Balk, Rikku... huh, that actually is rather beatable, so he probably does win there. Heavy Repede has no shot, he's eating Auron Armor Break + Dehuai physical + Jeremy shot which should be deadly. Godlike's been covered. Amusingly enough, I think Repede loses to Janeless Light as well - yes, it's DEFENSE BUFFED SELPHIE HYPE there as she Ends Repede while backed by healers.