The levelling curve in TOR seems firmly modeled after WoW, and as such it seems to suffer from the same focus on solo questing. I have just completed the questing on Dromund Kass, including all the side quests, Heroic group quests and two Flashpoints I saw along the way [though I skipped the PvP]. I am now level 19, and am informed that my next story quest is in a zone labelled [explicitly within the game UI] with a level range of 16-20.
My first instinct as a WoW player is to skip that zone and get an early start on a higher level, presumably less overlevelled-faceroll one, maybe do a Flashpoint or two, but then it occurred to me that I'm on a storyline. Can I just skip this portion of the story and pick it up again in the next zone? [And is it too much to hope for a fully-voiced "Previously, on Star Wars"-style recap?] Are there multiple class questlines or just one? If it is just one, would not doing that zone totally derail my class quest line and make me unable to continue? Will I really need to skip all the additional content and side quests just to keep from out-levelling the story?
First-world problems, I suppose. It's probably too much to ask for a game to be offer challenging content by default. Any challenge needs to be bypassable, and the game tuned for people who cannot complete it.
On a related note, the significant other and I wiped two or three times on the first boss in Hammer Station before we conceded that we would need a dedicated healer. I wouldn't have it any other way. The more this game kills me the more I like it.