Guild Wars 2

Right now,I am farming 1st boss with 4/5 gambits with my thief, someone told me eles can be extremely good at farming (boss dead in 8 seconds good) so can anyone share some thoughts or a build designed for farm?

http://gw2skills.net/editor/?fFAQFAWnMISPDW2AuMAdEGIAwI9ECHAOAJgx5gZwSE-T1RBABRcBAuS53N7PgnOAAeAAUq+jZKBBA-w

Do 5 gambits. Drop eruption, and unsteady ground; drop lava font and start a meteor shower. Use arcane shield as necessary, as well as elemental. Otherwise blast your fire fields for might while doing this with arcane wave and your heal.

Even when you go down, the extra lava font should be doing massive dmg.