Both are viable. I'd say that if you're going with Stalker for on-demand invis, faster recharge gives you a lot of flexibility with Blink Strike to have it up almost whenever you need it. However, in tougher/above-your-level PvE content, sustained melee is NOT an option, so I'd swap back to the invis.Hmm, should I keep a fast recharge or invisibility on blink?
Ludicrous. Invisibility drops you off radar in PvP. PvP is massively about radar and positioning. It's huge.Invisibility is useless in pvp, but its great during pve for reviving teammates. You'll probably need to use increased duration.
Vanish is the one thing I can't recommend. Showstopper is too good an R2.Yes, I might also put the invisibility on my arc blade special. Though, it eats up a lot of precious seconds.