If I Metronome Extreme Speed will I gain its priority, or will it just rely on the user's speed? (Basically, will it be a normal attack) I ask because how I'm thinking it works is, Metronome selects the move prior to both opponents attack.
Metronome does not gain priority from selecting priority attacks.
Since the move is randomly selected when you choose the move how would it know to give you priority?
Source: http://bulbapedia.bulbagarden.net/wiki/Metronome_(move) scroll a little bit
because metronome generates the move when it is used not when it is selected. if you move first and get vital throw you still move first and if you move last and use extreme speed you still go last.