Well here are many ideas.
I know you already made Patchy over Peach but since she is a sorcerer, wouldn't she fit more in Zelda? Plus you can also add Koakuma over Sheik. Alice too would look nice on Zelda but peach is ok.
Just as an idea too, you can add the Prismrivers over the Starfox team, just a wild thought xD
Medicine could be a nice idea for small characters like Ness, Lucas or maybe Olimar >__>
Satori over Lucario seems fine but I think she would fit for small characters too? Koishi over Sonic sounds weird.
And as another note well just a thought you can mix Hatate and Aya in a Zelda and Sheik pack.
Btw I really think Miko needs a revision <___< I really use her alot but I don't like how her sword moves, I think someone over here posted a new model which also was more accurate to HM.
Yatsuhashi could go well over Pit too, but you can also if you wish make another Zelda/Sheik set for those Tsukogami sisters.
For Raiko well I found a model if interested
http://otakum7k2.deviantart.com/art/MMD-Touhou-Raiko-Horikawa-Download-394623977 and even thought over Zelda looks nice an interesting take would be DK (Just for the bongos but I think it will look weird so I don't know, ) but due to her drumset Ike could fit too. I can also see her over Ganondorf with a taunt that draws the drumset.
Sukuna can fit over Mario as his taunt can make him change size.
Well I think those are all of my sugestions, overall I think you are doing an excelent job.
Always hail Kyouma.