Don't mean to be rude or anything but most of that is wrong.
Standard opener for Arcane Mage using Class Trinket + Prophecy of Fear is as follows: AB->AB->Drop PC (wait for the GCD)->Use Arcane Power and spam AB on the crystal. Assuming Prophecy procs on the crystal dump all available Arcane Missile procs. If Prophepcy procs on the boss and you have AM procs use them on the boss (debatable whether or not it's worth but in my experience it is). Otherwise keep spamming AB on the Crystal, once it dies switch to boss until AP is over and then Evocation to full mana.
Assuming Prophecy procs on the boss within the first 2 ABs keep casting until you get 4 stacks of AB and then drop PC->AP. If you get ANY procs of Arcane Missiles simply use them and immediately after you shoot out the last AM drop Crystal at the boss (wait for GCD), Arcane Power and spam AB on the Crystal.
More or less one of these cases are going to happen on every pull