How did they figure counter-rotating props would increase pilot workload? You don't do anything different when managing the engines....don't get this at all.
I bet he meant would NOT increase pilot work load. With counter rotating props the engines would cancel out the torque allowing the pilot less work with the rudder and ailerons. IIRC, the benefits to the Mossi in having counter rotating props (dont remember which engines were tested) was about 8 mph in level flight at 5,000 ft. In the big picture it wasn't really necessary since the Mossi was already as fast as it was.
Though, I suppose one could argue that with the torque present there would be less work involved when rolling or turning to the favored side.

As far as the bomb selector goes, I agree that it sometimes gets a bit confusing as to which set of bombs a player has selected because unless you fly that plane quite a bit it is easy to lose track of which set of bombs is selected. I fly the Mossi Mk IV quite a bit and I know the first set is the bomb bay and the 2nd the wings. I drop the wing bombs first then the bomb bay, the biggest pain is having to hit the backspace key while zoomed in and not knowing if I've gone over the cannons and selected the bomb bay or not. I almost with we could have separate triggers for bomb bay and external bombs.
This is very similar to being able to select X turret with X button while in a bomber. Few of the bombers match up.