It is not very clear - which gates are allowed? any 1Q gate, and for 2Q gate only CX?
That does seem to be correct.
The QASM code is how we can verify the 2-qubit gate count and/or circuit depth. It should include only CX and single-qubit unitary gates. This note on our Discourse support site might help.
Yes, that’s correct. Any unitary 1Q gate as well as 2-qubit CX gate