Bladedancer has never been very good for PvE purposes. Sometimes there is some niche use for invisibility but that's about it. Nightstalker is usually the best choice for PvE for Hunter, that's why it was added to the game. For PvP however Bladedancer is still very good, personally my favourite class. I am pretty good at the game with well over 400 hours invested in PvP alone. Pick Skip Grenade, Backstab and Fleet Footed (because Quickdraw got nerfed) from the skill tree and you're good to go. Hunters how ever take probably the most skill to use efficiently. Titans are by faaaaaaaaar the easiest class to use so just level up your Striker or Sunbreaker and go get the easy mode kills in PvP.