One note on #2: In a coasting descent, two riders of equal weight can out-descend a solo rider of the same weight on a straight course (no cornering skills needed). For the pair, the rear rider can coast up into the leader's draft with a fair bit of speed differential. At that point, he can push the lead rider (hand on hip), giving him the energy saved in the draft, or he can come around and use that energy to pass the other rider. This can be repeated and is significantly faster than solo coasting. The pushing version is much more efficient since it keeps the frontal area of the pair lower compared to side-by-side passing.
Throw pedaling and rider weight in the mix, and it all still applies. Multiple heavier riders who couldn't keep up on the climb are going to destroy a solo pocket climber on the descent, even if everyone knows how to descend.