Yeah Rumia is indeed underrated would love to see her again in a later Touhou with some new spells up her sleeve. Ah the struggle is real being a fan of a character that rarely makes appearances haha. And yeah I doubt it too she may not appear again but then again Zun surprises often so who knows maybe she may just come back I mean in the 16th game someone as minor as Lily White came back.
Oh wow you play better than I do on TH6 I usually end up start using continues on stage 5 one day I will 1cc..ah I did manage to 1cc the 5th Touhou game before 2 times actually!