Wait, I think I'm confused. Is "Marisa doesn't need a broom to fly" a thing about Marisa here, or is it Touhou canon that's inherited here, or what? Because if it's Touhou canon, that's definitely something I missed. (Or could have come in after I stopped paying close attention, I guess.)
I know I've seen one fanfic that ran with "Marisa needed the broom to fly to start with, but later she learned how to fly without it (which is why she's still alive), but keeps using the broom anyway for style". But it's Touhou fanfic, so you can never tell what came from where.