Okay, if I have a seneschal character and I get Basic Weapon Training (Universal) as a starting Talent, why is it a 500 XP Rank 1 advance? From what I read, a) the Universal group gives you access to all the weapons in that group (you don't have one talent for las, one for bolt, and so on) and b) nothing states you can take a talent multiple times to get a bonus.

Is this errata, and what am I missing?

It's there for redundancy so 1) you know how much that talent costs in case the GM allows the player to exchange starting talents for XP for different builds, and 2) for the future when possibly backgrounds or other character add-ons alter the starting skill list, so you can always get your basic skills.

Someone really needs to sticky this, or people need to use search more. These sorts of questions have been asked at least once or twice a week.