Research Update:

I tried the 45 Holy / 16 Ret spec I listed above.  It actually ended up being 39/16 since my toon is only lvl 64.

I went out to Zangramarsh to test it.

I put on all the +Str warrior-style plate I had, and with my improved Blessing of Might, I got up to about 1,000 AP.  I was using the Hellreaver from Ramparts (slow 68.8 DPS polearm with +Str and +Melee Crit)

The bottom line – I just wasn’t satisfied at all with the talent template.  I’m sure healing dungeons would be fine, but questing DPS was lackluster.  It wasn’t much better than being protection, and I gave up all the damage mitigation.

I tried Seal of Command with Judged Crusader on the mobs.  Command just doesn’t proc enough IMO.  It’s ok when it does.  When you get a crit, it’s fantastic.  Without the talents really deep in the Ret tree, it just wasn’t crit-ing enough.  I seemed to proc normally about 1 in 4 or 5 swings.  Command would do about 385 dmg on a normal proc.

I then tried Seal of Blood.  That was better than Seal of Command.  It would proc for 185 dmg and only do 18 points back to me.  The proc amount was lower, BUT it went off every single swing.  It easily added up to more damage.  4x185=740 is much better than 1x385=385.  The judgments on Seal of Blood and non-stunned Seal of Command were about equal.

It boils down to a fundamental incompatibility between Holy and Retribution.  Holy has talents to help spell crits, and it also has deeper talents to help spell damage.  The Holy tree strongly implies getting +Spell Damage and lots of +Int (because 35% is converted to Spell Damage in addition to increased spell crit).

Seal of Command and Blood seem to imply lots of Strength and Melee Crit.  They are based on weapon damage.

So what seemed to happen was that Holy talents were gimping my Retribution damage, and Retribution gear was gimping my Holy damage (and healing during down time between fights).  I was constantly running out of mana.

I tried using Seal of Righteousness with the big 2-hander, and I found that it was doing more damage per swing than Seal of Blood.  The judgement was also a little bigger, and it didn’t feedback 33% of the damage to me.  Seal of Righteousness was doing like 240 points per swing and 520 point judgments.  It was better than Blood and more dependable than Command.

Sooo… I went back to the drawing board.

I respected again.  This time dumping the idea of Retribution gear and talents.  I picked up Improved Seal of Righteousness (adding +15% damage to that seal) and every other Holy talent I wanted.  I put 47 points into Holy, and put the remaining 8 points available into Protection for Improved Devotion Aura and Precision (which also affects spell hit).

I changed into my best +Int and +Spell Damage gear.  I went to the AH and bought a green 2-hand sword with +Int and +28 Spell Damage (70.2 DPS I think, slow 3.6 speed).

That synergy of talents and gear made a dramatic difference.

I ran Devotion Aura to mitigate some incoming damage.  I ran Blessing of Wisdom to regen mana while fighting.  I judged Crusader on mobs to debuff them, then ran with Seal of Righteousness as my weapon buff.

I was doing 400 point normal procs with Seal of Righteousness every swing.  In addition, my Holy Shocks went up a lot too.  I was getting 700 point or so Holy Shocks that would crit for about 1,000 sometimes.  If I used Divine Favor to guarantee a crit, and used my Vengeance of the Illidari trinket for a Spell Dmg boost, my Holy Shock was almost 1,200 points.

The nice thing though, with Improved Blessing of Wisdom running and more mana efficiency, I wasn’t seeing as much down time.  My heals in between fights were also better.

I’m not saying this is better than a pure Retribution template for pure questing, but it was tolerable.  It made for quicker single-mob kills than Protection.

So basically, I ended up with a toned-down Shockadin build.  I’m not going for Sanctity Aura in Retribution, which is the true cookie-cutter Shockadin build.  This is still pretty workable it seems for leveling.

I might yank the 8 points from Protection and put them into Retribution.  That would only be for the purpose of getting Improved Seal of the Crusader and Improved Judgment.  I would not go any deeper there.