(edited by RainbowDanish.6819)
Build help Nade/Bomb
This is the bomb build I use:
http://gw2skills.net/editor/?fcAQFAElIq6Znuy3dkAki67XRKyvl/8QupttA
Although I use berserker/ruby orb gear.
Bomb #1 is your auto attack, Rifle #3 and #5 on CD. Include BoB on defiant bosses. I run with Poultry Soup for condition removal. Sometimes Elixir B is swapped with Elixir C. Sometimes Rocket Boots (amazing for dropping aggro) gets swapped with Elixir R.
On bosses that are impractical to melee, I’ll swap a trait and utility to use Grenades. Grenades are a pretty big DPS loss though.
In terms of your build, I would recommend using swiftness on crit and vigor on swiftness traits. An extra dodge is worth an entire set of toughness.