I think Lucas is just as bad with his actors as he was back in the day (and think about this: if you knew you were being filmed for a doc, wouldn't you take the opportunity to dispell the myth that you can't communicate with actors?).

Despite Lucas, the original cast had a chemistry which this new cast lacks. I think it's because the original cast had sets, props, locations, etc. to "get them in the mood." This new cast spends 90% of its time shadowboxing in front of blue/green screens. The actors are never brought into the Star Wars world, so how are they expected to act like they're really in the world?