Basic circuit validity problem
Here's my take on it. But your question might tred on "opinion" a bit. The following includes any rational I think appropriate to clarify my choice.


Invalid. The current source is looking at infinite impedance and cannot drive its current through that. The only possible option would be 0 A. But that's an oddity and not this case.
Valid. A voltage source can create a potential difference between two open nodes. A solo voltage source can exist.
Valid. Same as just one resistor with the sum of those two values. A solo resistance between two nodes can exist.
Valid. A current source has no difficulty driving its current through a short circuit.
Invalid. A voltage source cannot develop a voltage across a short circuit. The only possible option would be 0 V. But that's an oddity and not this case.
Valid. The resistor is irrelevant, since the current source current will develop 0 V across the resistor. But that doesn't change the fact that you can put a resistor across a short circuit.
Valid. The voltage source will produce a current in the resistor. The difference between this current and the current source will then flow through the voltage source. No conflict. (The voltage source power may be positive or negative. But this isn't an argument against it.)
Invalid. The current sources have different values. Not possible.
Valid. Adding the resistor allows the different valued current source a path for the remainder.
Valid. Adding the new resistor allows another path, but doesn't invoke any impossibilities.