Agreed, that is why I slot UMD and fit in some scroll mastery, it is also why I don't want to rely on a 95% success chance (that 5% always pops up at the worst time)For me it's more about if things go wrong or not having the ideal group, not necessarily just for raids as a backup healer.
I don't think you understand how statistical analysis works. You are not guaranteed that it will proc every 20 hits or 200 hits -- but you can reasonably estimate (over a significantly sized population), how often it will proc and the statistical advantage it give.
That said, I don't think you should calculate Conop and Lich form, maybe not even Demonic Shield, in the melee portion. It doesn't proc within the statistical 4-5 hits you'd get(conop 20hits, lich taking 10 hits, bracers taking 5 hits). On top of that, Conop procs hp or sp, so it's really 2.5% for the hp(also, I've seen it said it has a 4% proc rate, so 2% for hp). This would give Boon more weight but without all those other guards being assumed you miss the "+1 hit" mark.
In either case, the data is presented in a way that you can make your own choices as to which guards you run with.
I run Robe of Shadow for the +3 necro, Nullification and Superior void lore - Boon of undeath is just a bonus.
I agree with your assessment of the viability of nuking in EE; however, nullification spell power and void lore are of great concern as that directly corresponds to your healing ability.Assuming you can slot toughness and resistance elsewhere, it really comes down to the differences in spell power, arc aug, and dcs.
I don't consider nuking a priority in EEs, really just useful for bosses, in which case you can swap to 120/element mastery sticks. The sp you get from being able to twist in Endless Faith due to that extra int makes up a lot for that spell power though. 250+ sp for more nuking/dots, more heals(outdoing anything Boon has going for it), 30 sp echoes for energy burst(if you have it) or other stuff.
I don't know how Endless Faith provides more survivability .. sure it gives you more spell points, but unless I screw up, usually I have enough spell points to make it to the next shrine -- for the occasions that I don't, I can drink a pot (and for the price of your caster sticks, I can buy hundreds of major pots). Also the loss of superior lore is pretty major blow to your survivability -- having to slot that somewhere else means additional trade offs.
Allowing to twist Endless Faith for the 10% sp provides more survivability than Boon or even Boon and the extra nullification/lore(which is possible to match somewhat with 120 on one of the +3 sticks).
Congratulations on the Litany!And I have to say this; I just traded an Abbot seal for Litany in my last run of Abbot, my 21st!