Can you use a Template Weapon if one of your own Holoechos (a decoy) would be hit by the Template? So RAW it is not stated that a Holoecho is considered a real trooper in regards to declaring an Attack with a Template Weapon against it. But does that mean that the Holoecho is not considered a real trooper in regards to Templates, or did I overlook a ruling that clearly states this anywhere? Maybe this: If you read this as 'all three Holoechoes together represent the trooper', does this mean that of those three must be treated as a friendly trooper? Or is this "represent" weaker, and not the same as "are"...?
If the Trooper declares an attack, it Is considered revealed for the whole order and there will be no holoechos to affect.
It's not that easy, I'm afraid. Anytime a holographic decoy cancels its Holoecho state the player must remove its Holoecho from the table at the end of the Order that happened. An exception to this rule is made when the Holoecho fails a Coherency Check, then the player must remove the Holoecho immediately, before measuring movement, if he has declared any. Just remember that Holoechoes are not troopers.
I'd honestly say that you cannot Template one of your own Holoechoes, but I don't have a rules reference for it.
I would say that you cannot (even the owner of the skill templating his own decoy), because all cancellation clauses say to remove the markers at the end of the order, and you cannot affect friendly troops with your templates... and the Holoechoes are considered a friendly trooper (all three a single one, in short) in order to generate AROs and detonate mines, etc...
I think I have asked this question before and got told by IJW that echoes aren't troopers. I wouldn't give that answer much credence, though, it was some time ago on the old forums if memory serves.