If we wanted to, we could make this insane by including descriptive tags too. Does Danbooru have a tag limit? If nobody knows then this is a great chance to find out.
Because Kanako is the most powerful being in Gensokyo at present with a character profile, given that Shikieki is morally bound not to start sending just anyone to Hell for any reason.
Nope. The reason is that putting her alone at the top is the only way to fully show her logs and her shimenawa without blocking anyone or having them blocked. She does have the largest accessories in canon.
The artist didn't draw the characters from UFO... but I'm guessing that it's because she/he (I'm pretty sure Sankaku complex said she/he was a she) drew this before it was released...
Does anyone know who the two characters between Rika and classic Reimu are?