As far as canon is concerned, you don't need to be force sensitive to wield a saber. Look at the Clone Wars animated series (which is canon) and check out how many non-force users wield it. To include random people picking up the saber and slinging it around well enough to fight actual Jedi. Its just like any other weapon, with patience and training anyone would be able to wield a saber. It being lightweight and a blade of light only makes it more difficult to use, not impossible for anyone lacking force training.
As far as the duelist thing is concerned, generally anyone who has trained extensively with a saber will be better than someone who has not. In this case, the knight trains more with it than the consular.
