My B2 Plot Hooks (thus far)

Well, I've been reading through B2 Keep on the Borderland, and trying to decide on some plot hooks to incorporate to keep it from being all hack'n slash. Some things that are needed are connections to the people in the keep, goals while in the caverns, chances for roleplaying and negotiation, the chance to overcome some tricks and traps, and finally some mystery to keep the players wanting to investigate these caverns. Here are some ideas I've gotten and decided to write down, so they don't get forgotten; they're not presented in any order, and they are pretty rough right now:

1) Once the characters have established themselves, and been introduced to the Castellan, a memeber of his family could go missing (kidnapped by the priests of Chaos). I'm picturing the Castellan as an older man (mid forties-fifties), a rough frontier type noble very common sense and straight forward (probably not favoured by any distant "court". His son a promising heir with an expectant wife (don't know why).

2) If the Orcs capture the characters in the net trap, they may try to use the characters to rescue their brethern from the goblin/hobgoblin alliance, or to kill the hired "Big Guns" aka the Ogre. I see the proposed warring groups as splitting between lines of those aligned with the priests of chaos and more independent races. One idea I've been toying with is that the goblins are natural beings of chaos who are subservient to the priests while the orcs and gnolls are magically created to be superior, but proved to unreliable and rebelled against their masters.

3)The jewel merchant may have a story of a trusted seller coming with a famed necklace who barely survived an attack from tiny dog faced demons known to lair at the foreboding caves.

4)The hermit may have been an apprentice of Zelligar the Unknown. I don't want to dismiss Search of the Unknown, and the hermit maybe a nice link between the two. Aswell the Zelligar, and Rogahn may have fought the Priests ( or worked with them). Of course there is nothing set in stone here, just an idea to link the two modules. It would mean looking at how to show signs of this link in the adventures' tower-cavern complex though.

6) The treacherous priest the treacherous priest, oh what to do with the treacherous priest.

Well these are just some hooks I thought of using, there are still more to come. I also want to flesh out the priests of chaos a little bit : why are they there, what are their goals, are they a death cult, do they serve some elder evil god, how prevalent or powerful are they? While I don't want to restrict myself too much in the beginning; some history here would help.
My goal here is to leave pausible plot hooks without forcing a railroad plot on people. I'd like to know what others think; are any of these good ideas, too railroady, am I over-thinking this ( okay I probably am over thinking this, but its fun!).
I know there is a vocal group out there who have gone away from total world creation before getting started (and I for one agree), however I'd like to have a little background history to work with, as opposed to make it all up on the fly.