Actually I see BLM more like a debuffer than a dps. Sleep, lethargy and virus are decent debuffs. On top of that if you can get Fire 3 and a firestarter proc off then swiftcast + flare + insta fire 3 for a very nice burst.

Being said, it depends on the opponents and your teammates. Good tanks will interrupt you like mad and what you can do is run to your friend and have them help you >_<