Would the Life Cleric’s Disciple of Life feature work with the Necromancer Wizard’s Grim Harvest feature?

The Life Domain cleric’s Disciple of Life feature (PHB, p. 60) says:

Also starting at 1st level, your healing spells are more effective. Whenever you use a spell of 1st level or higher to restore hit points to a creature, the creature regains additional hit points equal to 2 + the spell’s level.

The School of Necromancy wizard’s Grim Harvest feature (PHB, p. 118) says:

At 2nd level, you gain the ability to reap life energy from creatures you kill with your spells. Once per turn when you kill one or more creatures with a spell of 1st level or higher, you regain hit points equal to twice the spell’s level, or three times its level if the spell belongs to the School of Necromancy. You don’t gain this benefit for killing constructs or undead.

Would the Life Cleric’s Disciple of Life feature work with the Necromancer Wizard’s Grim Harvest feature?

For instance, if I’m due to get 8 HP from Grim Harvest for killing a mob with a level 4 Spirit Guardians spell, do I get an extra 6 HP thanks to Disciple of Life?

How to deal with a non-force-sensitive character trying to harvest a saber cristal?

Greatings !

Three of my characters are close to lvl 7 and plan to enter the crystal cave on Mygeeto to harvest their own kyber cristal for their future weapons. This will be a standalone sidequest for them.

One of them is a scout with absolutely no force sensitivity. His goal is to build a weapon based on ligthsaber technology. He has no intention in becoming Force sensitive.

In my vision of the Star Wars universe one simply cannot power a weapon with a cristal without using the Force to build it, the item will explode. He has been warned in and out of character at several occasions.

But I’m really ensure how to deal with the cave part. It is supposed to give Force-induced vision to padawans to scare them or make them give up.

I don’t remember any instance of non-force-sensitive in movies or the novels I read going into this kind of place.

I cannot forbid him to go as his character knows the location now. I do not want them to harvest many cristal to benefit from it (they are quite rare and worth a lot of money).

Should I let him take any cristal he find ? Should I not let him find any cristal ? Should I make the vision so strong his character will give up ?