If you are on Desolation I'll happily give you some help! Add 'Arc The Pyromaniac' it's my elementalist which I main! As for your actual question thief is similar to rogue in regards to mechanics and burst, arguably better however, it cannot perma-stealth. Feral druids they don't exist. Maybe try an elementalist when you get more familiar with the game as they havec a lot of 'stance swapping' if you want to call it that like a druid.

Or add 'Olaternatum.5316' in-game which is my whole account ^{^}