Please reference Page 31 of the Rules Manual on how to activate multiple models simultaneously.
Correct.
Correct.
Correct.
It is now a Decoy model (models have their own AP). If it's revealed AFTER they've used all 6 AP, then it is still counted as being activated already.
The rule wording is much different than Artificial Soulstone. Also, it makes it so all 3 of them can't use a free Soulstone.