Hi!
You can solve your government reform problem by making the following two changes.

First change to the correct culture in \common\government_reforms\tohou_government_reforms.txt

Change all instances of "culture_group = Gensokyan" into "culture_group = Gensokyan_culture"

There is also a sprite import missing in \interface\contryview.gfx to fix the missing banner on the government reform tab.

Add the following import to the contryview.gfx file inside the spriteTypes object to use the standard banner from Dharma expansion:

spriteType = {
name = "GFX_government_reform_banner"
texturefile = "gfx//interface//government_reform_banner.dds"
noOfFrames = 1
loadType = "INGAME"
transparencecheck = yes
}

Hope this helps!
It would also be neat to see some Touhou specific government reforms in the future.