I'm in a similar situation trying to figure out the best setup for a 2011 OB for a ski box and two bike racks. I was recommended the Thule 450 R feet (I have a bunch of old Thule stuff I would like to use) by my local shop.It is a lot of weight, and we were pretty nervous, but it felt pretty stable. Those limits don't usually say much. Yakima and Thule bars are only rated at 165lbs a pair...
However, in terms of weight capacity, since the Thule feet would be attaching to the Subaru factory cross-bars in the undeployed position (essentially making them rails instead), wouldn't the weight limit still be the factory rails/cross bar 150 pounds?