I feel like I'm doing it wrong but I whenever I'm soloing I have to take it slow or else I'm going to die. I feel this way on my war, ele, engi. Maybe (probably) I'm just terrible at the game. --- http://i55.tinypic.com/2a9ntxe.jpg
Go Acrobatics/Shadow Arts with Dagger/Dagger and Signet of Malice.
You will have an insane amount of evasion via dodge rolls and dual wield skill. You will have an insane amount of stealth via things like shadow refuge and cloak and dagger. You will have an insane amount of healing via regeneration on stealth and multihitting with signet of malice.
And of course, stealth alone is great survivability for being to get out of all sorts of situations. Shadow Refuge lasts so long. --- Just call me HTM
ele and warrior have great survivability. however, ele are only as good as how well you play. stats wise, they are probably the most squishy. warrior is a lot easier to have great survivability. it's all about the build for warrior. very easy to play.
guardian easily at the top in survivability.
if you have trouble with warrior, i think you are just not adjusting to the game, coming from other game.
Stealth is mostly good for avoiding fights in PVE instead of engaging in them. It isn't true survivability because of this. --- Rest in Peace City of Heroes: April 27, 2004 - November 30, 2012. We will miss you. Cause of death: "Realignment of Company Focus" by NCsoft.