Question about Artillery Ballista of Focus Fire

I have a few questions that maybe some one who has used the gem can answer. I plan on using this gem as a main skill. I like totems and would like the challenge of playing it.

1. When the ballista fires and doesnt have the maximum amount of targets will it just default to the standard gems projectile pathing?

2. Does it target when firing or as it falls?

3. Does it change targets mid flight when if the original target dies.

Only a guess, haven't used the gem and wiki doesn't elaborate, so if no one knows, you might have to test it.

1. I think it probably only fires according to how the transfigured version works. So if you have less than maximum targets it might only fire at how many targets you have.

2. I would say when firing.

3. I doubt it, I think it would probably continue to target the corpse and then do aoe damage around the corpse location.

Only guesses, I'm uncertain about any of the answers.