GuildWars2Live: How important is following the personal storyline for a character's development?
Theo: It depends on the sense in which you mean “character's development.” In terms of power progression, the personal story is entirely optional. If it's not something you're interested in, you don't have to participate, as is the case with most of our content.
Leif: To expand a bit on what Theo said, every story instance scales you to the recommended level, and the content to how many friends come along. Even if you start engaging with your level 3 story at level 67, and bring along two friends that are 10 and 80, you should still have a fun time without one-shotting everything. That said, you'll get the best appreciation for the overall world setting by playing the story as it comes, since it helps to explain who exactly all these races and factions are—especially once you begin working alongside one of the Orders of Tyria.
Theo: That's just for power progression of course, if by character development you mean the sense of establishing your character's story and their relationship with the world around them, it's a key facet. The personal story is the narrative thread that guides your character through the game. It's where you determine who your character is and the role they play in the greater conflict.
Leif: I totally agree, it's absolutely key to establishing who your character is as a person and how they relate to and impact the world in a permanent way. Important characters may live or die depending on your choices in the story. Major battles are fought that turn the tide in a growing conflict. How you choose to proceed may lead to meeting someone new along the way. They'll move in to your home district, and you'll get the chance to know them even better. This is especially important as a sylvari, since you begin with no history other than your Dream. Who you meet helps establish who you are.