Meiling and Mystia as top tier only because they can solo the whole game.
Except that everyone can solo the whole game given an unreasonable level
Honestly a tier list is a bit ugh for me.
For example, Yukari is really pretty bad if you have reimu to hakurei barrier (and you have ran to use her def buff as well), and you don't deliberately go out of your way to manage your entire party's speed formulas to work around her spiriting away spell (or if you're using kaggy as well, which also screws it up).
Yukari's spiriting away is what I assume what makes yukari strong in your opinion, and if your party isn't organized to specifically work around that very spell, it's really pretty shitty all things considered. So the tank gets an extra turn to..switch? focus? hit for 0? ok wow. Yukari doesn't get an extra turn. So that leaves 2 characters who did not get a full bar that was empty, but was likely half-full+, at the cost of an entire bar of Yukari's who is already slow to begin with?
My point isn't that the spell sucks, it's just that you have to deliberately go out of your way to make it good to use it's admitably great potential.
I also find that you actually do favor dps over support. Why is suwako rated so high? What does she have other than great dps? Her defenses are really bad, and she has absolutely no support other than iron ring's par. Which is only useful for the burninator/reisen (boss-wise, for trash, aoe par is king, other bosses not par-reliable are easy enough already).
I also think favoring chen over remi means you have weighted preference to dps. Remi, can at least provide the party with a viable offtank. Iai slashes, demon blade dances, etc. Remi can take them in the 2nd slot WHILE doing respectable dps, where respectable is actually really excellent if you don't have iku/Keine/Some dedicated atk buffer... If you do, yeah, remi is average..But so is chen isn't she?
Anyway my point isn't to dispute. I'm just saying that the worth of each character in Touhou labyrinth is far too situational to really rank effectively imo. (Though I have to agree that mokou, Eirin, etc strikes me as not outstanding in ANY party setup).
I'm currently playing with a mag-based Yuyuko. My pervious attempt with her was unfortunately dissapointing. However, despite her slow leveling, her Mag growth isn't too shabby, and I find it VERY hard to believe that her effing 9Mag multiplier on flawless nirvana with average delay wont be jaw-dropping amazing by end game...Even if it's merely "very good" like Ko in 3 steps or something, she has excellent defenses for a non-tank...soo.