How does each key talent affect Warlock DPS?

How does each key talent affect my DPS?
Bane +20%
Bane reduces your Shadow Bolts from 3 seconds down to 2.5 seconds. This is a 20% increase in Shadow Bolt spam dps.

Math
In 15 seconds...
With Bane: (15 / 2.5) = 6 Shadow Bolts
Wout Bane: (15 / 3) = 5 Shadow Bolts
6 / 5 = 120%

• Demonic Sacrifice, Succubus +15%
  Increases your shadow damage by 15%, self explanatory. The greatest thing about Demonic Sacrifice is its versatility. In some prolonged fights where your raid may be strapped for healing, you can sacrifice a Voidwalker instead for the health regen. For AOE situations, you can sacrifice an imp for +15% fire damage. This especially shines on the dog packs in MC.
  
  
• Shadow Mastery +10%
  Increases your shadow damage by 10%, self explanatory.
  
  
• Ruin
  Ruin increases your dps by about half of your crit rate. So if your crit rate is 14%, your dps increase from Ruin is 7%.
  
  Math
  In 100 casts of 1 damage Shadow Bolts at a crit rate of 1%, your damage without Ruin will be 100 + 1(.5) = 100.5. With Ruin, your damage will be 100 + 1(1) = 101. 101 / 100.5 = .5% increase in dps. With enough +crit and +damage gear, Ruin can overtake Shadow Mastery in contribution to dps.
  
  
• Improved Shadow Bolt ~10%
  This is much more difficult to calculate since it depends on your crit rate, how many warlocks you have in the raid, how many of those warlocks have this talent, and what each of their crit rates are. However, since all of the best raiding builds have Ruin in it, chances are most to all raiding warlocks will have this talent and with good gear, Improved Shadow Bolt should be up much of the time. Watch for it next time; with 3-5 warlocks in your raid, Shadow Vulnerability from this talent will be on the mob very often. Also, ISB increases all shadow DoTs as long as it is active. ISB also increases the value of each +1% crit you get from gear, which in turn makes it more valuable than +1% hit in many situations.
  
  See Question: "How much does Improved Shadow Bolt improve warlock dps?"
  
  
• Improved Corruption
  Improved Corruption is as good as it looks on paper and moreso depending on the situation. Some people will tell you that the bonus you receive from this talent is only half a second (2 sec regular castime - 1.5 sec global cooldown = .5 sec). This is correct to a certain extent, except there are several factors they are not taking into consideration: you get a 2 second head start in ticks since Corruption begins the moment it is applied and every time it is reapplied; when there are multiple mobs present, the time saved from this talent adds up even more. You can also move while you're casting Corruption, which is its biggest benefit.
  
  
• Improved Life Tap
  Life Tap is one of our best and most used spells. However, every second you spend Life Tapping cuts into your dps. At just two points, Improved Life Tap gives you 20% more mana, which will add to your dps.