Paladin has lower DPS but higher mitigation. IMO it could benefit mostly from further buffs to its mitigation as opposed to increased DPS. We already have WAR for DPS tank but in order to retain balance Paladin really needs to be better at the one reason you would pick it over WAR - needed extra damage mitigation...

Buffing some gladiator skills would be good I feel like.

Rampart still 20% for 20 seconds but 45 second cool down
Sentinel 35% for 15 seconds 90 second cool down
Provoke 25 second cool down (buffs WAR and DRK too but why not?)

Then for Paladin skills...

Cover - Take magic damage too, 15% damage reduction (gives a reason to use it)
Hallowed Ground - 300 second cool down
Shelltron - Block the next *attack* that deals over 15% max HP for 10 seconds 40 seconds cool down
New Skill - Divine Intervention level 59 - Fully heal all allies and removes status effects (uses all MP and TP) 420 second cool down