I use QWERTY too, I'm just pricky about shift/spacebar x)
I'm simply just not too confortable with them for no particular reason lol.
Idk what would be a better fit honestly, since both hands are already all busy with WASD and arrows, but I believe I myself would feel better by taking my hands out of the arrow keys for a split second to press the [;:] key right above them (at least on my keyboard they're right above them lol, my arrow keys are kinda squished). Altought now that I think about it I'm kinda dumb too since by that logic I could be doing that to use the right shift instead, since it also is right above my arrow keys x3
About the visibility issues I think this could have been solved by some better color coding, or maybe even giving Reimu and/or her hitbox a more vibrant outline or something like that so it stands out more among the chaos. I didn't realize the dashing didn't had i-frames at the end tho, but yes that would have been very welcome too, actually.
Thanks for replying btw :D