Wall of text inc., sorry if the text sounds harsh sometimes, it's not my intention
So the stats get their value from 2 things at the same time:
1) how much more your heals hit for if you get the stat
2) how much longer can you heal for and thus do more overall healing
Your quote didn't really clarify everything:
1) why is 1int=1healing, when 1crit=20.34healing and with bok 24.38int=1crit?
using above weights, we get 1int=20.34*1/24.38=0.834healing
if we don't include the mana pool gained. Then again, there wasn't any calculations how much
the increased mana pool is worth in healing.
2) why is 1mp5=1.91healing, when based on the rank4 FoL calculations:
32mp5 = 286.92 more healing done in 5sec (3casts)
<=>1mp5 = 8.96625
now we want to know how much more we need +healing to heal that much more in 3 casts
(8.96625/3)/(15/35) (why was coefficient 48% when it should be 42.857%? nost thing?)
we get that 1mp5=6.97375healing for FoL R4 when you cast 90% of the time.
3) why is 1crit=20.34healing?
lets take the gear quoted, you will heal with r4 FoL on average
234.64+829*(15/35)*1.0868=620.7645
increasing your crit by 1% you will heal for 0.5% more which is
3.1038 more, which is 3.1038/(15/35)=7.242healing
and you save 0.01*90mana per cast. If we take previous example of 3 casts in 5sec,
you will save 2.7mana in 5seconds which is 2.7mp5.
so if we use your 1mp5=1.92healing,
1crit=7.242+2.7*1.91=12.399healing
based on previously calculated new 1mp5=8.697375healing we get
1crit=7.242+2.7*8.97375=31.47healing
**EDIT: And these values would again change how much 1int is worth, to either <0.6healing or >1.3healing
4) why was rank4 FoL used as the only example?
(I don't propose those new calculated weights as the real weights, I only calculated them
with the info given above to prove that something seems wrong with the stat weights.)
Shouldn't we calculate how long we can heal for with specific gear, buffs, consumables, spell and
cast% and
a)calculate how much more healing 1 cast gains from specific stats
b)calculate how much more total healing we can do before going oom with specific stats
Then use a) stat weights when you know you dont go oom, and use b) stat weights
when you know you need the extra mana.
In case a) mp5 is worthless, int only gains value because it gives crit, and crit
only gains value from the increased healing it does, not from illumination
In case b) mp5, int and crit will gain huge value because they give you mana so you can
do more overall healing during the encounter at the cost of HPS.
All in all this won't change the BIS gear lists much (or in some cases at all) for pure healing
and you will still clear all of vanilla with competent healing squad if you use old stat weights.
This new info will mostly be useful for ppl who want to save on consumables (eh), their raid team
isn't the best(dps low, other healers slack, bad tactics, overhealing, etc) and speedclears.
In speedclears you want to maximize your healing capability so you can drop healers for more dps
(especially in AQ40/naxx where you might have to start casting FoL 100% of the time with reduced
healing squad and the encounters will take longer than 5 minutes so you might have to stack some
mp5/crit/int). And of course we don't want to give people false information.
Ideally we would have 1 BIS list for pure healing and another list with nice replacements which give
you mp5/crit/int for reasons listed above.