First of all, I would remove most ship to projectile momentum transfer to the Artemis. It is a rocket with airfoils, which are designed to keep a rocket on its path. The physics are completely different than an aerodynamic spinning bullet.
Since that won't happen, speed the Artemis back up to 75% of its initial speed, and remove some of the damage and AOE instead. Making a low skill gun harder to hit with as a nerf is silly. Not hitting a target is no fun for new players that don't understand the wonky Guns physics (I will prove yet that they are wonky!).
As for burst, yes, remove the extra clip. Then increase secondary damage a touch since it is supposed to effect Burst. This will make it slightly more viable on non-AOE guns. Reduce AOE increase a touch. Then slow the projectile 10%.
End result: An Artemis with Burst that is slightly faster than current Art, does a little more damage per missile than vanilla, with an AOE between current vanilla and current Burst, and normal clip size.
And yes, remove AOE for Charged, but give it a hell of a wallop.