A list of what is unlocked by level anywhere?

[Erendis]

Level (5-15) - Unlocks levequests (I can't recall when exactly this happens)
Level 10 - Unlocks guildhests
Level 10 - Unlocks Inn rooms.

Level 9 story quest unlocks leves and inn room. Then you can unlock guildhests.

[Mhaeric]

Level 9 story quest unlocks leves and inn room. Then you can unlock guildhests.

Guildhests are unlocked with a level 10 quest called "Simply the Hest (Starting City)."

You are correct about the level 9 story quest being the one that unlocks the inn room. Every character I've done it with has always been level 10 by then, so I forgot to double check the actual level of the quest to unlock it.

I went back to find the level of the quest to unlock levequests and it is level 10. In Gridania it is called, "Leves of Bentbranch." Despite the levequest NPC in town having level 1 and level 5 levequests, I remember them not being accessible until you completed this quest. I.e. the level 9 story quest reward just allows you to access that quest, which must then be done in order to actually do a levequest. You can probably do the quest at level 9, which involves doing a unique levequest, but you can't turn it in to unlock the rest until level 10. That may have changed.