I do not, in general, like hook beginnings. Some stories want a hook, and some want a net. Mind you, I'm OCDish enough that I have only once that I can remember since 1990 not finished a novel that I started.  Your milage may vary - and probably does, because I think in kilometres.

Three opening paragraph(ish)s of mine:

--
To tell a tale should be a simple thing.  They are not little deeds, these
of which I write.  To set down heroic acts as they occurred, one after the other
in order from beginning to end, should be enough to bring into being a romance
fit to fire a dead man's heart.  And yet it is not.  Before quill touch scroll
or spell of remembrance mark the world, there are a thousand thousand decisions
to be made.  I have cursed my tale and consigned it to perdition in yonder fire
more times than you would well credit, and yet.  And yet.  The story must be
told.  I do not doubt that some wretched poxy half-telling of those times has
made its way to your ear - minstrels will earn their drink on it until all
worlds' end, and with no more of truth in their recitals than in any other
tawdry ballad told over a fire.  I wish my tale to shine forth true and bright
as steel, and find myself at once perplexed.
--

There had been thirty thousand humans on the Cyrano de Bergerac when it arrived in this system; thirty thousand individuals of that extroverted, fascinating, endlessly strange species had come to live on the planet which they named Elysium, a hundred and fifty Earth years and nearly two hundred of the planet's own in the past. DeepSight had no idea how many more lives thirty thousand humans might bring into being over that span of time, with a whole planet to fill, but the number would not be small.

According to the signals there were twenty-eight of them left alive in the Elysium system.
--
They think they understand it, now, this Secretary of State Linebarger and his bleedin' shadow soldiers. They give me these books to read and take my notes and comments as if it mattered. They think they know where it began and why it came out this way and why the rats are here in the Big Apple after my hide, after so long. And maybe they do. But they weren't there at the beginning, and I was, before anyone knew who Onkel Adolf was, before the Iron Moons and Mosley and the Bomb and everything. To listen to them, you'd think it was that poor mad bastard in Serbia who set the course of the twentieth century, but I was there ten years later when the shot came that really changed history, shivering in the rain on Upper Mount Street in ratty old pants and boots way too big for me, in O'Sullivan's squad that had made a bollocks of things as usual, waiting for word from the Big Fella to tell us what to do next. Seemed so little at the time, just another street fight in a city full of street fighting, but I remember it, oh yes; March 22nd in the year of Our Lord nineteen hundred and twenty-eight, at half-past ten in the morning. I was there the day Jack Kennedy died.

As of this summer's exciting adventure in home-buying, I finally have a study of my own to write in, with a nice big double bed in which to sprawl with my laptop and notes spread out around me.  At the risk of sounding fourteen, one of the things I like best about it is that the walls are all dark red.

Unfortunately, my writing habits of working from after work Friday into the small hours of Saturday morning and then sleeping late on Saturday are kind of impaired by the people upstairs having small children sleeping in the room above my study, who get out of bed at 6 am and have discovered that jumping off the bed onto the floor really hard and loud is Fun.  But with luck they will grow out of it.

I tend to get plot as "here is key scene A that happens about the middle.  Here is key scene B that happens right next to the end. Now what can you do to get the right set of people to be in the right places and react in the right ways to make a story out of this ?" I'm not comfortable starting without knowing where I am going, but it's very rare for me to write more than a couple of thousand words without them telling me something new and useful that can feed in to that process; my outlines are tools to be continually refined and updated, they don't actually match  the book well until the book's written and usually rewritten a couple of times too.

It depends.  *puts English major hat on*  Technically...no.  But for character speech, and for things that are written in first person (which is really just more character speech), it's more acceptable.  Pretty sure you could probably get away with it some, I doubt there's any contraction police that are gonna come around and bust you for it (except the people that do my editing for me. Oi.)

Voice is character.  Sam Spade and d'Artagnan will use contractions in very different ways. Do what's right for the character.

The thing I finished first draft of at the end of October, first half of a duology*, is almost dead on a hundred thousand words.  From previous experience, that will probably go down by about 10% all the way through on further passes.

The thing I read back through and tightened since then, is 149,048 words. I want to reread the end of that where I made most of the changes on this pass one more time to be sure it flows, and then I'll be thinking about finding it a home.

*I'm not sure whether to call it one book or two, but at that length it's unlikely to be bound as one physical object; first half is fairly standard story-shaped adolescent protagonist in world-saving situation, second half will be same character middle-aged with two kids discovering the world's not as saved as it appeared and having family responsibilities and not just being able to rush off and have adventures any more. The gap between them is sort of "and then we went away and became fishmongers and did nothing with the plot nature for the next twenty-two years".

It depends on what the story is.

What comes to me first is usually either a story shape or a world.  So I often find myself doing the metaphorical equivalent of shouting into the darkness at the back of my head "OK, I've got a vacancy here, 1998 real-world setting, male, early 20s, nurturer, pretty much asexual, has to be someone who will respond to key event X this way in chapter 9 and behave this way in key scene Y in chapter 27. Any takers ?" Then when someone turns up who can fit that part, I start writing and learn about them as I go along - got a whole subplot out of that guy, largely to do with a couple of younger people assuming that because he was not noticably responding to women in a couple of situations where they assumed all straight men would, he must be gay rather than just someone with almost no sex drive; and there was his family background, and what he did with his life, and so on. Complications ensued.  On the other hand, I get people who come out of that darkness and don't fit any current projects and just sort of mill around, more or less well-behaved.

My work and home situation is such that I usually get to write one night a week, and it's usually Friday; I try to finish a chapter, or at least come to a reasonable break point within a chapter, every session.  [ My chapters tend to come out between two and four thousand words, for what that's worth. ]

It's certainly easier to get going again when the next bit is going to be fun and I know how it goes, but the combination of being a bit obsessive-compulsive and knowing I have limited time to do this in usually gets me putting words on the screen even when the next bit does not appear immensely exciting.

Has anyone stumbled across a series - or even a lone book - that fits the bill.  It would have to be fairly new - or fairly old - as I've read just about everything on the B&N bookshelf.

Oh, also, Gerard Houarner's The Beast that was Max and Road to Hell are sort of in this direction; paranormal assassin rather than detective, but it's a similarish sort of world.  Fair warning; they are very dark indeed, in a bloody rather than an existential sort of way.