Just a couple criticisms on your Destro spec info: While 3/13/55 is your standard spec,
shadowfury is a wasted point. In raids, there is little or no use for it. Moving that point into Demonic Embrace is probably a better choice.
For Locks with better gear, or those who have reached the hit cap via gear, a 0/13/58 spec is a must. Something around
this is a decent choice. Soul Leech and Improved Soul Leech will add some utility, survivability, and let you get a couple more casts in before you have to tap.
As for the Destro rotation, it's actually more effective to (Curse), Immolate, Conflag, Chaos Bolt, Incinerate fill. The damage boost from Pyroclasm outweighs the .3 or .4 second wait.