Find your niche.
Why wouldn't it be rated E? Personally, I think a little romance wouldn't hurt the game. But it is pretty awkward for the male protagonist to not have anything, haha.
Anyway, I'm inclined to agree with Jellicent. Even though I think the rival will be more helpful and concerned at your progress rather than cocky. He does look like he can be a bit like Gary and Silver, but I really want his appearance to not dictate his actions, especially towards you. Or better yet, they should continue on giving good character development into the rival like the old games. Maybe he can turn dark, against the protagonist in the story maybe, then go back to the way he was, with a better resolve and experience or something. Or just follow the usual development and make the character go from really cocky and "Imma beat you in strength all the time!" to a changed man.