In my dating days the door issue was indeed telling. In Yeshivisha circles if a girl was particular about this, it was a bad sign. Stam for one party to open the door for the other is indeed mentchlich. But for the expectation to exist that particularly the guy do it for the girl, this idea comes from outside cultures (b’cholkoseihem).
To do it as a kibud, surely a husband and wife both have an obligation to honor one another. (Perhaps they should each open the others door!)