There's nothing special about it being worth less than a dollar; it's an arbitrary mark not unlike a year ending in zero. But it only happens when the euro is significantly weaker than it was intended to be.
This isn't how central banks value their fiat currency.
If for some reason the Fed puts 20% interest on the USD, the value of the USD would increase dramatically. The Euro is under no obligation to set its value with respect to the USD or the Pound.
There is no "intended" value of the Euro with respect to other currencies.
There's an "intended" value of the Euro with respect to keeping European governments solvent and keeping prices steadily increasing.
If the Euro has to drop to $0.01 to achieve those goals, it will. If it has to climb to $100 to achieve those goals, it will.
Central banks do have some thumb on that scale, but as you say, it's entirely about keeping the economies healthy, not maintaining any specific ratio to other currencies. If it has fallen so far that the ratio is 1.0, that's not a problem for the currency itself, but it does happen because the economy is struggling more than the American economy is.
This is just a baseless assertion you’ve made repeatedly. You should provide some source and be a tad less aggressive about it if you want to be convincing.
This is completely false. For example, the ECB targets 1 EUR = 7.46038 DKK.