Did some more testing, and it turns out we're both right. The macro you laid out works as described if you have the required 40 RP before hitting the macro. If you hit the macro with <40 RP, you'll get a "Spell not ready yet" error. Combat status does not seem to affect the macro either way.

Not sure if that's a bug or intended behavior, but heads-up all. Will look for a workaround and post back...

(edit)
SmithReplica, testing this apparent bug against your macro....and it looks like your's is unaffected. Naus I would recommend using SmithReplica's macro instead.

Well, using the macro does not mean you HAVE to insta-sac the ghoul, it just means you don't need yet another keybind (or the need to click) for Death Pact.

Timing your CD's is an excellent point, but there's also the simple fact that you cannot cast Raise Dead and Death Pact within a single GCD, as the ghoul has a summoning animation. There will be time for 1-2 GCD between the two spells, making this a very dangerous "oh crap" button if you summon the ghoul after the need for Death Pact heals arises.

And I always forget that I can use an AoD ghoul with Death Pact. Thanks for the reminder.

Exactly !

I use the castsequence macro, and it happens that, when needed (or anticipated), I just summun the ghoul and then, when I need it, click the macro again for the heal. Saving one bind for that is really useful and allow me to have the same macro with ERW (for the RP in case of emergency + low RP) on another bind.

I am pretty sure it does. However you are not completely wrong since there is some sort of lag between the ghoul appearing and AoE protection kicking in so you are better off not summoning right into AoE (it is either this or he spawns with low health before the game realizes he should have full health and gives him that; freshly summoned Hunter and Warlock pets have the same problem). He will be fine for subsequent AoEs though.

It happened to me a few times already that I summoned the ghoul a few seconds before electrocute (tanking Nefarian), only to find him dead already after the electrocute. Sadly my minion is stupid enough to stand right behind Nefarian, so it's either the tailswipe or the electrocute that kills him.
Does anyone have experience with this too, or can I find somewhere in worldoflogs / combatlog what happened to my minion? I have searched both extensively but I can't recover any info about the minion.

Ghouls actually have the -90% AoE damage. I even wasn't aware of that, but browsing to some of my recent logs I found that : World of Logs - Real Time Raid Analysis
You can see that my ghoul took one single Static Shock, which is supposed to deal 5K damage, and just suffered 500 dmg.

Regarding the early vulnerability while it has just been summoned, I'm afraid this log is no use as the ghoul seemed to have lasted a few seconds (so the conclusion that the Static Shock was taken early can't be made).

Stacking Mastery and the nature of Runic Empowerment don't seem conducive to the Lichborne talent. Lichborne itself is an "oh shit" reactionary heal, yet it requires RP pooling for it to have any real benefit - which essentially means you have to "prepare" for something you only need in an emergency. The problem with pooling RP is that it's not actively being used for RE procs, which convert to Mastery-infused Death Strikes which are supposed to prevent Lichborne situations in the first place (DC heals still proc RE, though). The other issue with pooling RP is that you risk capping it, which is more RE procs lost and even less Death Strikes.

Lichborne is also ridiculously expensive talent-wise, since Icy Reach is awful for tanking and RPM is useless without Lichborne itself. It's a lot of points for a highly situational survival cooldown. Sadly there's no other real options for survivability, but I think Crimson Scourge is worth looking at. DK aoe snap threat is fairly awful (especially when OB is on cooldown), but it's worth noting that the free Bloodboil procs are also a free 10 RP - and every 3 of them translate into a chance at an RE proc (meaning more Death Strikes). Maxing Epidemic is also useful, since the extra duration allows for a few more runes to be spent on DS. Since DKs are advised to bias Mastery, taking talents that result in more DS (and to a lesser extent, threat) seems viable, if not better.

Crimson Scourge doesn't actually give you that much RP because you can't always use that proc. There's a lot of times when CS can proc and you have to reapply diseases, DS, RS, HS, or do something else on the GCD (Bone Shield, DRW, DnD, etc). Also if you use a CS proc with your B runes down, it doesn't actually trigger Blade Barrier so you still have to prioritize BB which can lead to CS falling off or a proc overwrite which just makes it lose value.

I respec in and out of CS for AoE fights (Halfus, Maloriak), but even then I rarely keep using BB, I usually BBx4 or x6 with DRW up and then I just go back to HS'ing but that proc has never made or broken a rotation.

You aren't supposed to have 130 RP for Lichborne all the time but you can always use it once and then generate more RP and then use it again. The main thing with LB is to reliably (no miss dodge parry) bring yourself to a non-dangerous HP level which can definitely be achieved with only 1 or 2 DCs.

I really don't understand how every few weeks I see people posting about how 'bad / worthless / clunky / expensive / non-conducive / etc' that Lichborne is.

Here's the deal:

-Like you even said in your post, there are NO other viable survival options. What is the point of 'not' picking it up? I have had it save me in too many situations to even think for a split second about dropping the talent. Sure you're sacrificing 3 or so RS that could potentially be RE procs, but you're doing so in 100% guarantee that you can pump 4 or so 30k+ Death Coils into yourself (or much more if you combine w/ VB or GS).

-Lichborne isn't some cd where you just mash one button and then continue doing what you were doing. It's an 'advanced' cooldown that requires both foresight and timing. I explained this in depth back in the old Cata DK thread:

old Cataclysm DK endgame tanking [4.x]

I highly recommend reading that post and applying it to your DK tank theorycrafting.

-If you're having issues with your 'snap' threat, then you're defiantly missing something that won't be fixed with picking up CS. DK has some of the best, if not THE best, burst and sustained threat out of all the tanks right now. It's to the point of me being able to pull Sinestra without even getting tricks cast on me (give it to a dps for more of a dmg gain) and only needing an MD (gcd used by the hunter before the pull for zero dps loss).

That's the entire point of picking it up. There ARE times where you are going to need a 50-60k heal in raids and instead of just sitting there and taking a potentially lethal hit from the boss. You can top yourself off or self heal much more w/ each GCD with LB than you can w/ DS.

Saying you find yourself in situations where it's rarely used doesn't mean the value and importance of picking it up isn't there. It just means you aren't putting yourself in situations that are hard enough, situations where healers aren't stretched to the limit to buy dps, situations where boss dmg intake is insane because you're in inferior gear (aka progression) etc.

No matter what you do, and how good you are at 'cycling your runes' you're going to have quite alot of situations where you can't DS and have to fill that gap w/ some sort of cd/self heal. Situations like that happen and they happen very often on progression. Tank through current content in non BiS gear and then let me know if you still feel the same way.

What this comes down to is in black and white, as I've said dozens of times. Lichborne is 'required' if you're going to be a serious endgame DK tank that wants to have every possible variable available to stay alive.