Ye, you really should put 2 points in Art of War.
Good idea to make 2 different healing keys, one with hardcasting (so you have a way to heal without art of war) and one with /stopcasting in macro to use flash of light with art of war without hardcasting.
Also make a macro for accepting popups (you are swapping between windows to queue and accept dungeon, you can just press macro twice and it queues and accept basically instantly without swapping between clients), I use this one:
/script AcceptTrade();
/script RetrieveCorpse();
/click LFDRoleCheckPopupAcceptButton
/click LFDDungeonReadyDialogEnterDungeonButton
/script RepopMe();
/click StaticPopup1Button1
In jamba I recommend to use "Slaves Opt Out of Loot" on Team -> Core: Team page, it makes slaves pass on loot so just press greed on leader to get the items and then trade any item you want to give to slaves (since you can trade BoP items from dungeons for a while).
You could use all 3 judgements (Light/Wisdom/Justice), you are only using Justice so you miss out on hp and mana regen.
One thing you can set up is to use Hand of Reckoning on slaves first then on tank, that way you can use it as a dps ability with a short cd. (8 sec cd and deals a lot of damage, at lvl 80 4 paladins can kill a non elite with just 1 hand of reckoning each)
You really should try to use Exorcism when not in close range (or with art of war proc) and not hard cast heals with tank since you lose all avoidance while casting.