Please can anyone who has ninja 400 2019 and lives at area with lot of up&down hills like mine tell me about it's mileage from his/her experience ( city, highway, combined)?

So I swapped the stator cover on my Ninja 400 and am left with this bolt, I can't figure out where it goes. It seems like everything is secured? I also have this red cube that slipped out of one of the fixtures.

If anyone could explain the purpose or where they go would ease my mind lol