Forest Spirit:
Now that I think about the characters I have written over the years almost every one of them did included hidden hooks in the background. Only very rarely they ever materialized in the games, but they were there so they could have been used against my characters.
Yeah, I've found that most well-written backstories will have plenty of plot hooks buried in them already. The player can help things along by leaving lots of things left dangling, but ultimately it's up to the ST to decide which ones fit their particular game.
In my particular case, I tend to use a lot of player backstory material to add setting elements, create initial plot premises, and tie stuff in with the backstory material of other PCs. I think nearly half of the plotlines in my current game originated with player-submitted stuff (though it's probably not very straightforward and obvious to the players by the time they see it).
On the flip side, most GMs I've played for tend to ignore my backstories completely. They're mainly interested in the stats, and already have their own external storylines in mind that they want to run. I don't see anything wrong with that - it's just different styles of roleplaying and I enjoy playing both ways.
Forest Spirit:
However, what I find so intimidating about coming up with a list of hooks when applying for a new game is that I don't feel I can know the specific setting well enough to presume to make such suggestions.
I agree. Most of the time it should be the ST's job to figure that part of it out, not the players'. Unless the game explicitly states that the setting is a collaborative work with everyone while the ST plans to take a back seat (I've seen those work well too, occasionally).