If they weren't so worried about class mirrors, I really would see the sorceror as a WoW Warlock... healing would be fueled by the destruction of others (Madness tree has some of this, but it's really just focused on self-healing rather than healing allies). Healing and buffing would be for a price. Nothing is free with Mephistopheles, except maybe the first taste. After that, someone's gotta pay. Don't know of a way to do that in a video game, though.
SpoilerIt's the same VA (Kristoffer Tabori). He's older. They also may be using different software to "robot-ize" his voice. At least he doesn't sound like T-Pain.
Alts are definitely a different experience. Even the different ACs play fairly differently. Where a Juggernaut/Guardian seems slow and plodding, a Sentinel/Marauder is quite active, even if they share a lot of powers and the same rage mechanic. An Operative/Scoundrel and a Sniper/Gunslinger are also quite different, right from the outset.
I like the first two. The third is kind of goofy.
I'd be less worried about catching something as I would be worried that they're the psycho ex-lover you were always warned about. Jaesa is definitely a bunny-boiler.