So I'm looking for a solid, preferably official, lvl 1 FR module to kick a campaign off with. I know Twilight Tomb starts at level 3, but is there anything before that? Do any of the source books have worthwhile kick starters in them?
Also, this archived site might help you obtain some useful adventures. While not specifically designed for the Forgotten Realms, it takes little creativity to arrange it so it in the Realms. As for the 1st level adventures presented here, I've DM'ed A Dark and Stormy Knight (based near Cormyr) and The Burning Plague (used the existing lore of Glister in the Moonsea region). Both of which were lots of fun and not too powerful for level 1 characters to overcome.
"Myteries o the Moonsea" 3.5e supplement contains a lot of little adventures for Level 1 characters and higher. It's a suggested campaign based around the Moonsea which can be easily extended with "Sons of Gruumsh" Adventure Module.
I used it as starting point for a "Moonsea North + Vaasa" campaign centered on Glister .
The mentioned misteldale adventure in the dungeon mag (there is a sequel in Dungeon #100!) for a dalelands centered campaign.