Pluck, grit, and determination. It's pretty clear that all of the protagonists are "strong" in the Force, even if they can't see, or use it.
Every character can use the Force.
At least if u finished one Jedi / Sith class story every other characters in your legacy will receive a Jedi / Sith power. My Trooper and Smuggler can use Legacy Force Project and Legacy Sweep - under Heroic Moment. So in rare occasions non-Jedi toons can use Force abilites.