Tsubaki’s charge cancel is actually pretty bad - the BEST it can be is even on frames, and that’s ONLY if she does it after 5CC; Doing it after 5B, 5BB, or 5C leaves her at -2, and if for some reason she should do it after 2B, she’s -4. The only real advantage it gives her is the fact that she can reset pressure at any time… as long as she is willing to reset from being -frames, which isn’t exactly really good. Compare to, say, Hazama, who can reset pressure with like 4 different moves all of which leave him at +frames. So basically, just mash and Tsubaki loses. In fact, just mash a lot. If you block pretty much anything, she’s at minus frames, so go to town. The only way Tsubaki wins is if the opponent respects her too much or if she just flat out outplays her opponent.
Also, I have no idea what you are talking about with Valk’s “power coming at the price of his speed” since his 5A is 6 frames - same as most of the cast (like, say, Tsubaki…) his 2A is 7 frames, again, the same as most of the cast. 5B is 10 frames - same as most of the cast and so on and so forth. Valk’s normals are thoroughly average in terms of speed - while he doesn’t have any especially fast moves, neither does he have especially slow ones, and unlike certain characters whose names start with Ts, he has frame advantage off several normals, and a special move that can be used to close ground and is still neutral on block. Oh, and what “frame disadvantage” does his 5A have? It’s even, just like Ragna’s, Hazama’s, and a bunch of other characters. Completely average again.
So yeah, I don’t really think Valk is “giving up” much of anything. Certainly Ragna isn’t. Also, I really don’t understand why people keep representing Ragna as having “predicatable” mixups. Why is a character that can throw a 20 frame overhead after literally everything “predictable” in his mixup? What’s that you say? It’s -11? Sure, but it can be cancelled at ANY TIME into a followup with 100P1. And Ragna gains heat like mad anyway. And has some of the best normals in the game from a space control perspective, and gets 4k meterless from his basic overhead - even at max range. Ragna deserved none of the buffs he got going into EX. They could have transitioned CS2 Ragna to EX and he’d have been 100% balanced. (He was arguably a little below average in CS2, but EX is supposed to be a slightly lower powered game.)