There are two bugs with Destruction warlock default script that I repeatedly fix.

First, is the display of Arcane Torrent over other cooldowns (like Summon Infernal). Arcane Torrent is hardly useful for a Destruction warlock except in the most extreme rare circumstance where the warlock might run up to a target to interrupt it as an emergency measure. This ability should not be higher in priority than major DPS cooldowns like Summon Doomguard or Infernal. The simplest fix is the comment out the line that includes Arcane Torrent.

The second bug is a major defect for Destruction warlocks with the Roaring Blaze talent. The current script has the warlock re-casting Immolate any time the remaining time on the debuff is less than the duration of the debuff;

target.DebuffRemaining(immolate_debuff) <= BaseDuration(immolate_debuff

Clearly this is incorrect. This causes Roaring Blaze warlocks to overcast both Immolate and a follow-up Conflagrate, greatly reducing DPS output.

A quick inspection of the code reveals that the pattern should be when the remaining time on the debuff is equal to 30% of the debuff diuration:

target.DebuffRemaining(immolate_debuff) <= (BaseDuration(immolate_debuff) * 0.3)

I have attached the modified base script so that you can DIFF the changes:

CWL Destruction Script.txt