By the way VEJ it's not only a company procedure that the commander (JAR OPS phrase) must do the take off with RVR below 400m it' s required by JAR OPS as it is a LVTO.
For all carriers I worked for the FO was allowed to fly each other sector only LVTO and CAT II/III approaches must have been flown by the commander. Even in some companies FO's may taxi the aircraft, what is actually possible on Airbus. If you check the Airbus SOP's they make a difference between PF and PNF, so the PF does everything including engine start, taxi out, take off, landing, taxi in and shut down the engines.