The glitch field acts like gen 1
1)This means attacks are based on move type not on the move itself. Pretty much the eeveelution types plus dragon are special and everything else is physical.
2)If using a special attack it will take the users higher special stat to apply damage (e.g. chansey using a special move would use special defence.
3)I think what you described is right here.
4)Bird is a reference to Missingo's type from the gen 1 games.
5) I once again think that you are right. Neutral means 1x damage.