I ususally do not reef until winds are in excess of 20 kts. If "weather helm" is an issue I'll let out the main a bit to move my center of effort back. VMG may even be better after the adjustment(also may have to bear off the wind a bit).
As far as down wind, you most likely had the right idea since the jib would be mostly blocked by the main.
This is my two cents worth, I am sure others will add more.