So I'm hashing things out - love my theorycrafting.

For Retribution Paladins, since their DPS is pretty good and it makes switching to Protection easy if it doesn't work.
Divine Shield talent, where it auto casts if a shot kills you and brings you to 20% hp. This is amazing.
Word of Glory - you've got 8 AoE heal bombs every minute that heal for 900 spell power. I'm guessing this heal is in the 1 to 1.5 mil heal range?
Blessing of Kings - it's essentially healing rain if I read this right - without the issue of throwing it down. it makes an absorption shield which is 1.8 x spell power - every 6 seconds. Where Healing rain is 50% spell power + 50% spell power x 2.5 over 9 seconds.
Blessing of Wisdom - another mini heal , it's something!

Flash of Light is still viable if you need to top off. I know not optimal but it's another tool in the arsenal.
Currently only lvl 35 on my team, and only using flash of light since the fights are not difficult. It runs butter smooth but excited to try it at later levels.

The Protection artifact weapon buff where light of the protector gives a 15 second heal over time on top of the instant heal is massive though. Ultimately Paladins appear to be extremely boxer friendly, but I love to squeeze out the DPS and I think Ret might have enough survivability for some situations.