Need some WHM Speedrunning tips please

[Saseal]

I try not to regen right off (unless I was not expecting that high of a damage) because of the delay between the next time I cast cure/II. I've had too many tanks drop from doing that x_x I only plop regen on right off if the mob is a more normal size (and then I can help DPS, too).

*deep breath and prepares to shield face*

I think I have a more defensive approach compared to some of the other tips, as I have a preference to wait till the tank is more stabilized before throwing a Holy into the mix

What I do for pugged parties is this (Take this as a grain of salt, since I seem to have a slightly different approach from everyone else):

-Protect
-Swiftcast SSII (because ain't nobody got time for standing. -_-)

Once I've realized that they're speed running (by their grabbing everything and then continue running):
-I keep the tank focused/selected (but this is generally majority of the run)
-When I identify that they're not continuing their pull (no more nearby monsters or theres a road block), I use Presence of Mind (my preference of the two buffs.... *shields face, since the rest of the thread seems to use Divine first* EXPLANATION: I've just found I can't seem to cast fast enough - I'd get one cure II in and they'd die in mid cast of the second. So I compensated this way, rather than Divine. You may not have the same issue or thought process as I so try either as a starter to see what works for you)
-Spam Cure II + SoS for enmity/MP
-Regen when they're -completely- topped off by a cure and I -think- they can withstand a few hits for the GCD (so in other words, not right away)
-Since I play on PC, I keep my cursor positioned over Benediction, just in case of an 'ohshit' emergencies while key spamming cures, and not hitting the wrong key in a panic. It's just a click away.

-If they're still not able to keep up HP even after presence goes down and theres still lots of monsters (low DPS, no AoE... tank shouldn't be pulling big without, but whatever), I pop Divine seal as a backup. It's really rare that I've had to use BOTH in one pull, and I really don't recommend it - because they're probably not going to wait for one or the other buff to come off CD for the next big pull (from my experience).
But at that point, hopefully you need to let them know to hold up a minute, at least for Presence. By then it might be 3/4 off CD.
I've only ever had to blow through both once. Ever. And it was frightening.
I've had tanks pull from entry to first boss and I still didn't have to do that. *twitch*

-At a certain point, I observe how much damage the tank is taking and if I can factor in cast time to DPS or Holy, then I'll do it - if not just to stun.

Normally I rotate the two between pulls - one big pull = Presence; second big pull = Divine; Third = Presence, etc

I have a preference of not using medica II because I encounter a LOT of tanks and DPS that a.) don't wait and don't care that everything they go near is about to come at me bro (and DPS running off before the tank), b.) They don't flash anything as they're pulling... just run through and continue (TANKS PLEEAASEE FLASH YOUR STUFF ALONG THE WAY ;_; It makes me too nervous to drop a heal too soon! *scared*), c.) too busy heal bombing x_x

[Spoekes]

When I identify that they're not continuing their pull (no more nearby monsters or theres a road block), I use Presence of Mind (my preference of the two buffs.... *shields face, since the rest of the thread seems to use Divine first*)
-Spam Cure II + SoS for enmity/MP
-Regen when they're -completely- topped off by a cure and I -think- they can withstand a few hits for the GCD (so in other words, not right away)

Let me try to explain you why, in theory, it is better to use Divine Seal first:
If you use Presence of Mind, you cast 20% faster. This increases healing by a flat 20% and also increases your mana usage by 20%.
If you use Shroud like you mentioned, you burn it away quickly and your aggro at that moment will half, but you are spamming cure 2 with 20% more speed. Its better to use shroud at roughly 70% and once you really built some amount of aggro worth reducing.

Divine Seal on the other hand increases heal for a flat 30%. Without increasing mana cost.
Divined Seal'ed Regen ticks really strong, thats why it pay off casting with DS. Medica II will even more increase the heal over time ticks, so you buy yourself time to either holy spam or regen mana and or use cure instead of cure II.

[Saseal]

Let me try to explain you why, in theory, it is better to use Divine Seal first:.

Okay, yeah - I see what you're saying - I'll try it the next time I end up in a speed run - and hopefully turn for a better strat.
I think my method of thinking just got burned into me too early by (possibly undergeared?) tanks that barely survived one cast of cure x_x (when I first encountered speed runs)