I just did some math for about 10 minutes, and came up with this being around a ~333 DPS increase, or a 4% damage increase for 0/13/58. It's more than that if you include the extra 1.5 or so conflag crits you get, and the extra 1.5 pyroclasms that result. I haven't figured out how to calculate that yet, but I'll get to it, but it definitely changed my perceptions of this as a nerf.

Please-check my math and let me know if I'm missing something.

These numbers are all from the sim numbers in the first post in this thread.

F&B Nerf:
Damage of Incin/Chaos Bolt reduced by 5%
7931 DPS
Incinerate and Chaos Bolt together are 65% of the DPS
7931x.65x.05= 257 DPS loss

Now the hard part.....
So, when your imp crits, your next spell previously had 20% more chance to crit. This is worked into the sim already, which is why this is so damn hard, because it skews the crit chances of the other spells. However, I think it’s doable. In the sim, in a 5 minute fight, the imp cast 161 times, with an 18% crit chance (and a no miss rate? Confused there, but it makes our changes easier, since we don’t have to add in resisted “would-be crits”). So that means the imp crit 28-30 times. That means 28-30 auto-crits.

Now we just have to figure out which spells would benefit from the buff, if it’s completely evenly distributed (no other way to do it, I think....)
20 Chaos bolts
28 Conflags
19 Immolate
127 Incinerate
Total of 194 spells

So Chaos Bolt has a 10.3% chance of being the next spell cast, Conflag has a 14.4% chance, Immolate has a 9.7% chance, Incinerate has a 65.6% chance of being the next spell cast. So that means:
Number of 100% crit rates: (We’ll assume 30 auto crits for simplicity). Also rounding to nearest number
Chaos Bolt-30*.103=3
Conflagrate 30*.144=4
Immolate=30*.097=3
Incinerate=30*.656=20

So, now, how many extra crits does that lead to? Crit rates of the spells, from the sim (This includes the current incarnation of Empowered Imp, so, it’s just the difference between 20% and 100%, not 100% and nothing. That’s where the math gets a little sketchy, but I think it still works if it’s evenly distributed.):
Chaos Bolt: 46.4%
Conflagrate: 68.2%
Immolate: 45.4%
Incinerate: 51.4%
So, now, what do we do? We see how many extra crits would happen, by removing crits that would have otherwise happened.
So, 53.6% of the time, Chaos Bolt gets an extra crit.
32.8% Conflag does
54.6% Immolate does
48.6% Incinerate does.
So now we multiply across....
1.59 extra crits for Chaos Bolt
1.312 for Conflag
1.638 for Immolate
9.72 for Incinerate

How much damage is that? Take average crits (I am multiplying average crits of Chaos Bolt & Incinerate by .95 to compensate for their 5% reduced damage)
Chaos Bolt: 1.59x16571x.95=25030 extra damage
Conflag: 1.312x15644=20524 extra damage (AND EXTRA PYROCLASM PROC)
Immolate: 1.638x4530=7420 extra damage
Incinerate: 9.72x13463x.95=124317 extra damage
Grand total of 177291 extra damage. How much DPS?
177291/60/5=590.27 dps increase?
590.27-257=333 DPS or a 4% overall dps increase from the proposed 3.2 changes
.
Also, there’s an extra 1.5 pyroclasm procs in there somewhere, and I can’t figure out how in the world I would mathcraft that.

Not entirely. The pet will scale of our chance to hit- our chance to hit is not effected by misery, but rather misery effects our target's chance to be hit. The difference is that it's a stat change to our target, and no stat change occurs on our "character sheet". So unless Blizzard creates a work around for that, our pets will be sitting at 6.5 out of 8% hit and 21 out of 26 expertise.

This is a well thought post. I understand now..

If blizzard gave us our target's debuff (Misery) if it is up on the boss, reflected on our character sheet, we would gain that extra 3% hit, and it would reflect on our pets too?

It would have to be a buff instead of a debuff. Basically misery does not change any of our stats, and as such it would typically not scale with this. I don't think Blizzard intended for this problem (Rather they were probably trying to make it so that hunter's caster pets would also be hitcapped), so perhaps they'll find a way around it. I've created a thread about the issue on the EU forums, but... No one ever goes there, /sigh.

only true for the hit part (IFF) but the pet is still missing out on expertise as 'motif pointed out.

Improved Faerie Fire and Misery are only spell hit, our felguard, succubus, fel hunter, voidwalker- do not benefit.

Misery and IFF does affect the felguard because im only at 13% hit yet my felguard never misses on a boss. His attacks are only dodged but this is do to lack of expertise.

Kinda :p
I don't know Pawn, but I think that my latest release has something that Pawn doesn't have.
There is now another extra line added on tooltips, that represents your full gear dps gain. The neat thing is that you can set a aimed hit cap that you want to set for your gear only, and it will be taken into account. For example, if you plan to get 4% hit from raid buffs, you can set your gear hit cap at 13%. All the extra hit that you currently have equipped, or that you might get from swapping a piece in, is therefore ignored.

I don't think you can evenly distribute empowered Imp procs across all spells. For a conflag to use the proc, the imp's crit must land at the precise moment between a previous spell cast *ending*, and conflag cast *beginning*. While Incinerate, for example, has it's full cast time where an Imp firebolt crit can land, conflag has only the mere millisecond of a window to gaint he buff.

Because of the quicker cast times of immolate and chaos bolt I would think these spells would get less, proportionally, of their share of procs.

Sorry if this has huge logic flaws but I have not seen this sort of idea posted elsewhere yet.

No, you've got the right idea, I figured that out right after I posted it and looked through it again, but I hoped someone else would come to the same conclusion-that Incinerate has a better chance to get the buff than the other spells based on its long cast time and the short cast time of conflag/immolate/chaos bolt.

Question is, how to mathcraft that without running the sim? That's where I'm at right now. Probably just going to run the sim and post the numbers with the proposed changes.

The napkin math I've done seems to be a fairly good guide, but certainly not precise in any way-it did, however, alleviate my fears that it was a small nerf, and it seems as though it's a small buff. Question is, how much of a buff is it, precisely?

I'll post my results once I alter and run a new sim, until then, I don't know how to mathcraft that issue-that Incinerate is much more likely to get the buff than Conflag/etc.

Thanks for the criticism, appreciate it-glad other people are looking at the math with a critical eye so we can find errors and find the precise answer. If anyone has a solution to this problem, I"d love to hear it. Otherwise, a simming I will go.

I made some quick changes to the SimCraft code and recompiled and it looks like the answer to this is:

1. For the 2 specs on the list that already use LT but do not use glyph=1 to force up-time (53/0/18 and 53/0/18 DG) I saw an increase of ~40-50dps by enforcing 100% up-time. However that is only about 0.5%.
2. For 0/13/58 replacing Immolate glyph with Life Tap and forcing 100% up-time resulted in around a 135dps increase, which is about 1.75%.

This is based off my own revisions to the 2610 release of SimCraft (updated to include the proposed changes to LT glyph, Pandemic, FnB and Empowered Imp), using 30k iterations of a 5 minute fight with the default SimCraft gear sets for T8. I did not test it on T7.

Note: This does not include the Replenishment changes, which could effect natural LT up-time, which could increase or decrease the effectiveness of forcing 100% up-time onto specs that already use it. It should not change the fact that LT glyph does appear to be one of the top 3 glyphs for each spec if the change goes through as it is listed now.