Can, or should, a non force user, or someone with no master/holocron/etc, be allowed to take ranks in saber with their xp between session? I'm thinking no, that this particular skill should be more story driven than others, even if the non force sensitive player has a saber. Thoughts?
Let me just stop you right there. This whole prejudiced attitude against non-force users and their ability to wield a lightsaber really needs to stop. You've got a great question on your hands, why muddy it up with this nonsense? We now have multiple examples in the canon of characters who fight using a lightsaber despite not having the force (or having any understanding of the Force even if they do have it). Han, Leia, Finn, Vizla, Grievous... even Cassie Cryar were all were able to fight with a lightsaber. At the end of the day, the ones with natural aptitude and training fared the best; same as any other weapon.