Iron Grip cuts ranged weapon recoil by a lot. It is a Tier 3 Ranged skill that keeps automatic rifles, SMGs and light machine guns on target in Horde fights.
Yes. It is one of the most useful Ranged skills for Horde fights.
Deadshot, Two Birds, One Bullet and Up The Ante.
Fire in bursts anyway. Even with low recoil, short bursts save ammo and keep shots on heads.