Wookiepedia says what really hindered Ben's growth is that he withdrew from the Force during the Vong crisis. The potential, however, remains within him. He's still Luke and Mara's son.
FOTJ does have him decapitating one of the Sith Sabers on his own. So that's something. Ben also defeated 3 Sith on Dromund Kaas. (His father and Jaina were busy killing 6 others)
...Maybe Ben Skywalker needs a respect thread.
For Force Powers, Ben has...
Skywalker was able to disappear in the Force, a rare power that was taught to him by Jacen Solo,[25] a power which he later taught to his mother. He also learned how to flow-walk, but after an unpleasant experience using the power, he vowed never to flow-walk again. Along with being very strong with the Force, Skywalker was a quick study; he learned to flow-walk in a short time[6] and was able to master sniping within hours.[25] Skywalker was also skilled in telepathy and was talented in reading a person's intentions through the Force.[1] Skywalker, much like his grandfather,[33] was very skilled with machines from a young age[5] and was also a skilled pilot.[9] Skywalker was skilled with stealth and infiltration, being able to evade detection on Centerpoint Station[1] and inconspicuously reaching the Amulet of Kalara's case.[24] Skywalker was also good with reasoning and logic, something that impressed his father during some of their dialogues,[9] and was able to convince Anakin Sal-Solo that he was actually a droid.[1] Skywalker was gifted with an uncanny ability to remember things he had seen or heard in near perfect detail.[25]
...No mention AT ALL of his telekinetics. Instead, they talk about the stealth powers he apparently inherited from Mara. All I can find is a reference of telekinetically throwing Vestara's Shikkar at Aboleth