Talents
53/0/18 Suppression + Cataclysm
53/0/15 Malediction + 3
Talent spec > * (I dare say) This is not a conclusion, but my way of thinking. I assume this is correct, or near the best.
It should be obvious which of the above specs are superior, if one has the chance to cap hit outside the talent tree.
The last three points can either be spent for optimizing some minor damage, or spec flexibility - like waiting with spending the three talent points until you know what situation your raid is in.
Hit Chance & Probability
If there is a 10% chance to be hit by a vechicle if you run blindfolded accross a highway, you might as well be hit all the times.
It is more correct to say: In 10% of the possible cases... And only if this game runs a static or smart Diminishing Returns on hit/miss, we can say that the probability is being taken care of and reassured by the game itself, making it statistically reliable.
However, while there is probability, there can only be reliability in 100%
Reliability CAN be somewhat priceless. It cannot be valued, but you can cap hit for precaution. Capping hit all the way to the 100% (yes, I know the cap is 17%) is preparing for the really shit timed misses, and possible multiple misses. Those of us who were hit capped -1% in TBC have probably all lived to see the magical 3-misses-in-a-row.
Probability is not reliable, and may as well be just as UNprobable if there is no Diminishing Returns.
I have only read Pages 1,2 & 5 so far, when making this post.
Edit:
Reliability also
somewhat requires your Hit Rating to be kept away from consumables, buffs and debuffs. If you die during an encounter (be it trash or a boss) you might save the day by being hit capped when resurrected. And maybe the 3% hit debuffer is dead at some point - shit
does happen.
Edit:
Let's say you have 99% chance to hit. You will do about 100 spellcasts during the encounter. Statistically, 1 of these spells will miss.
However, probability does not play within the same time-limit that you are. If 2 of your spells miss, you don't have time to change the encounter so that you may do 200 spellcasts. You lost 1% DPS. And even if you get the chance to do 200 spellcasts during the encounter, there are then 100 more spellcasts that may miss. Without (or even with) Diminishing Returns, all your 1-200 spellcasts can in theory miss. This is theorycrafting.