why aren't they showing Hayama

I think it's the first one

maybe to protect jun?

Well, spice boy was the winner in that other competition. So he might be treated a little differently.

Yeah probably I think it's a little twist because it's hard to think that he would lose so the only other option is that he has went to the dark side and if he has then probably Erina's dad is training his "God Nose" like he did with the "God Tongue"

I knew it that had to one of them to go to the dark side