Uhm, none of those instances give a Failed system message in the chat window. And really? Upgrade MM minions goes on cooldown when the target is out of range? I wouldn't know that one, however, if you Teleport Target on something that is out of range you get a popup over your character saying so and there is no cooldown like most skills do. But how exactly can you compare Missing a target in combat to using a power and flat out getting a Failed system message? O.O
Yea, the Teleport Target use to be two different powers merged into a single one, but I have no idea how they coded it because I am not about to go digging through the code to find out, I just hope that they coded it as a single function instead of activating one of two different powers. O.O
Yea snipes can be a little wonky, if the target moves behind an obstacle it will fail and go on full cooldown where other powers that are obstructed have no cooldown, but you are correct for powers that are interruptible they tend to have their cooldown cut in half if they are interrupted, have run into that with Aid Self too.
But I have not seen many powers give a flat out Failed system message in the chat window, see it much more often for things like trying to invite 'off sides' team members.
But yea, Teleport Target again, if a target is out of range, like a friend in another zone and sometimes even in the same zone if they are far enough away it just says so and there is no cooldown unlike Assemble the Team, and that is only a 10 second cooldown when it actually teleports someone which is a far cry from 30 minutes.
I can't imagine many people turn on System messages in their chat window, but I'm odd like that, and when I say it gives a Failed system message I mean it literally flat out says in the chat window that the power Failed, not missed or out of range or a buff ran out on its timer while I was AFK, it clearly states the power Failed, in fact the Mission Teleporter failed system message is quite informative and flat out says it has to be a Door Mission that is the active mission. So I apologize for any confusion not stating that sooner may have caused. ^.^