In my company the FO runs the show when it is thier PF sector, this includes calling for cx lists/eng stat/push, taxing, handling thrust levers (making stop decision if required) etc.
This works well and really engenders a good flight deck environment (CRM).
Clearly N. American airlines are MILES behind in terms of modern and enlightend SOP. As to only letting the (experienced) FO handle the aircraft in flight and normal ops- dreadful. When there is an emergency is an excellent time to hand the aircraft to the FO, (s)he will no doubt handle as well as the Capt and this frees up the Capts capacity to deal with and manage the emergency.
Just because the current captains had to go through their time as Flaps Operators does not mean it is the best system or that everybody else should go through it!