Please bare with me, I wish I knew how to make GSE macros that could work. Here is what I just came up with this evening once respecced to Demo for pre-patch.
This is basic spam casting for trash, etc.
/startattack
/petattack
/castsequence reset=target/combat Immolate,Curse of Agony,Corruption,Shadow Bolt,Shadow Bolt,Shadow Bolt,Shadow Bolt,Shadow Bolt,Corruption,Life Tap,Life Tap
This is for Meta start (boss fights, etc)
/petattack
/castsequence reset=target/combat Shadow Bolt,Immolate,Curse of Agony,Corruption,Metamorphosis,Immolation Aura,Shadow Cleave,Shadow Bolt,Shadow Bolt,Shadow Bolt,Shadow Cleave,Shadow Bolt,Shadow Bolt
Lastly, This is what I am currently using while questing 60+
/petattack
/castsequence reset=target/combat Immolate,Curse of Agony,Corruption,Life Tap,Drain Life
If you have any improvments would love to hear them, otherwise enjoy, hope it helps.