Factions/NF character on Proph

When you go from Nightfall or Factions to Prophecies, I understand that you start at Mission 6 or something. I really only want to play Prophecies because of the story (I want all three campaign stories ^_^), so do you miss out on a lot of the story when you don't start in Pre-Searing/Ascalon (i.e. Start at Lion's Arch)?

You'll miss out on some of the story if you start at Lion's Arch. But you can backtrack to Ascalon City (you can hire a runner in LA if you want) to start the story line. You won't be able to pick up any quests before LA, and I believe that you won't get XP for completing the Missions.

You can't get to pre-searing, but that's the tutorial area and the only thing, story-line wise, that you'll miss is the searing itself.

You don't miss out on much of the storyline, to be honest. The Prophecies missions before Lion's Arch really only set the scene for the real storyline. You can still backtrack to the earlier missions if you want to though, but don't expect any experience rewards (and backtracking to do them does count towards the Protector of Tyria title, as well as the Tyrian Cartography title so they're worth doing anyway).

You should start a character in prophecies to get the story. everyone should start one there, best introduction to the game bye far.