I really like the “lightsabers hurt you if you can’t use them” idea. Anyone can pick it up and turn it on, but, wihout learning the skill, by, say fighting and taking not-insignificant amounts of damage, and earning XP for the skill at a reduced rate, you can still do so. There’s precedent there for concepts that wield lightsabers without force training, Grievous, several Mandalores, Royal Guards, earlier Sith Assassins, the like. They don’t take to it the way force users do. Accidentally tagging yourself with a lightsaber is worse than getting an injury with a normal weapon though. Not sucking with it would be a LOT of training.
I do like the attunement idea. Maybe have that give bonuses and only be able to be used by force users? Maybe attuned sabers don’t break or something. Bonus Dark/Light damage?