Mistwell
Crusty Old Meatwad
I think that at this point it's probably easier to ignore "any amount or from any source destroys a minion", and simply look at what the statblock says:
HP 1; a missed attack can't damage a minion
In this way the temp hp rules are coherent with the normal monsters, minions still work the same way as before and there are no silly implications about non-damage.
Am i missing something?
I think either of two options is reasonable:
1) Ignore the "Ask Wizards" answer and go with the RAW DMG Minion clause, where any damage from a non-miss kills the minion, regardless of temporary hit points.
2) Ignore the RAW DMG Minion clause and go with the "Ask Wizards" answer (which is the answer you proposed as well), where you have to reduce temporary hit points to zero as well as their real hit points before the minion dies.
I suspect either option will work fine with most games. Number 2 slightly increases the power of minions, particularly if they have a leader in their group that grants temporary hit points to allies (which is not that uncommon). This will reduce the power of some class-types like the Controller, since many of their powers are intended to do very little damage but auto-kill minions. But, I still do not think option 2 would harm a game that much.
Personally, I am going with option 1.