Canon canon canon canon canon
I know, dude, I know. I'm actually really glad you mention it though! This harkens back to an issue that I struggled with when the ideas for RoSD were first gestating in my mind 3 years ago.
The universe of Touhou is so fertile, so ripe for interpretation and storytelling, that my talespinner's mind was working up its ideas not long after I started playing the Touhou games proper. I seriously did not want to write fanfiction because of all the negative stigma that goes along with it. I tried modifying the story in trivial ways that would keep it from being "touhou-related" but still allow an outlet for my ideas.
It wasn't long before I realized that, even if i change trivial things, it would still be Touhou fanfiction. I tried making a story about a priestess and a female magician who go on an adventure to stop some evil loli mage who was trying to poison the air.... and yeah it was going to be an EoSD rewrite no matter if I changed the names of things.
I realize I bastardize the canon. If ZUN got a translation of Ibunshu and read it... he'd probably laugh. And then hunt me down and beat me with the beer bottle he most recently emptied. I can only ask that people take the stories that Touhou inspires me to write unto themselves, and enjoy them for what they are.