My feedback for Lightsmith is, please do no do a ground pick up effect. It has been tried at least twice and failed each time due to it being hard to move or see the ability. This has been done on the Monk and Demon Hunter class already and it has been found unfun and simplified where it is a single button to pick up of the buff. Besides that the whole ability is pre-stack the ability for pull to have a buff during Hero/lust and your other abilities.
Honestly the play style fits better with holy than with protection, but for both specs neither are super mobile and having to interrupt casting(holy) just interrupts your throughput and when a DPS or tank is looking for a save the chances of them dragging dangerous stuff on top of your is very high. As for tank(protection) this just leads for a DPS possibly walking into a mechanic to grab the buff such as a boss cleave, boss frontal, AoE swirly, etc. Also moving from a protection side just leads to more micromanagement, buffs spawning in boss, mechanic, or on an unintentional person.
The other part that is being added the rotation between Bulwark and Sacred weapon again which is not a fun mechanic it got simplified due to it having to be gamed to work. This didn’t work with Dusk and Dawn in the Shadowlands iteration and it likely won’t work with the War Within either because players hate having to try to game a mechanic to play it effectively.
To give feedback, I’d say tie this into a current ability that is being used with the group that makes the character a disc priest lite with healing/shield/protection attributes. Paladins already have a ton of utility such as, Blessing of Freedom, Spellwarding, Protection, Sacrifice, Seasons, Word of Glory/Hand or the Protector. This fits well with Consecration, Shield of the Righteous, Word of Glory, Auras or in general changes the current existing Blessing spells into something ++. This would make it fit into the current play style better and give us agency where out buffs/help go.
With all the words above said, all I have to really say is please, please, please do no make this a ground buff/effect someone has to pick up, because it isn’t a fun mechanic and it is hard to see with particle effects, camera movement, and it doesn’t help the right people when it just get placed and it shields a person that doesn’t need it like a rogue or something.
Edit: Another thought I had, was give the Holy spec Hammer of the Righteous, and just have the buffs work similar to an Augmentation Evoker. Drop the main buff on your primary target/targets and using the main attack spell for both specs causes special buffs to get placed on both similar to a reverse beacon where is it builds a shield on each hit or dmg buff on a critical strikes. It will make Holy harder during save situations because heals go out but it might help even out those save situations where they aren’t so drastic and all we have is some quick heals from Holy Shock or Light of Dawn.