Here's a couple of changes that might be good for Paladin:

Cover- Target another party member to be covered (similar to Dance Partner). Every time you use Sheltron target member takes 5% less damage for 4 seconds.

Goring Blade- Make it 2mins and add this effect: Target hit by this attack suffers 2% more damage for 10secs.
Personally, I think if they want to make Paladin the "utility tank" SE should lean into it. With this change Paladin would be desirable in pretty much every type of content. However, Paladin should be on the bottom for personal DPS for Tanks (which they usually are anyway lol) if they were to have this kind of party buff.

Hollowed Ground- Make it a tiny puddle the size of the character hit box under the Paladin that makes them not take damage. Duration 10secs. If the Paladin moves off of it the puddle disappears and the effect ends. Change the recast timer to 5mins-5 1/2mins
A change like this would give Hallowed a significant disadvantage and put it more on par with the other invulns meaning a shorter recast timer makes sense.

Passage of Arms- This ability is too niche IMO. I'm not sure what to do about this one though. For me it just feels bad that to use this means I can't keep DPSing. In normal content it doesn't matter but, in hard content every GCD is important and if used at the 'wrong' point in your rotation it could me drifting FoF out of the burst window in part or entirely. Which could mean the group doesn't make the DPS check for the fight. I know you can flash this out for a server tic of Arms Up but, that doesn't seem like what SE wants for this ability.

What do you think of these thoughts? Good, Bad, indifferent?