No it is not.
It will be not very effective.
No, it's not. Rock resists Drill Peck.
Drill Peck is not super-effective on rock types. According to this site's data on the move, "Drill Peck deals damage with no additional effect, besides being able to hit non-adjacent Pokémon in triple battles.".
Irrelevant, but Drill Run is super-effective against Rock types because it is a Ground type move.
Hope this helped! :D