Despite of what you might hear, you can level up fairly easily with any class (even Prot warrior isn't as grueling as people will make you believe); and certainly as a rogue.

What is different from nowadays retail is that you need to group up, from area 2, for some quests as the last step (typically) of a quest chain might have you face elite mobs of about your level, which you might be able to solo, but it's slow and hard (and oftentimes simply impossible). This is also the case for some class quests which you absolutely won't be able to solo at your level (some, not all), so you rely on either kind strangers or friends, or you wait until you are several levels higher than what the quest says. Personally, I even help opposing faction with those, and I'm probably not alone.

You could skip these quests, but you shouldn't - it's fun and more social at an early point in the game.