Lo siento FernadoC, I responded to the above request and a treatment is not a conventional outline. So I guess I would ask: Did you find what you were looking for?
Your treatment suggestion was helpful actually, so no worries. As for whether not I've found what I was looking for...well I've gotten a few pretty good suggestions and pieces of advice so far which have helped me look at things a bit differently.
You have answered your own question here: what direction a specific chapter needs to take? Towards the ending, of course! Always towards the ending. I'm a planner, but I admit I'm a bit of a pantser around the middle myself. I never do anything I don't need to do, be it a timeline, a map, an outline. I do these things as I go along, if I need them. Most times I don't need to do them all, depending on the story/setting/time frame. I've been where you are, lost in the middle, and that's when I decided to outline what scenes were needed to get me to the ending. Something tells me you're overthinking this, maybe that bit about rewriting chapters before you finish your first draft. That would be insane for me. Maybe you need to know the story better before you start writing it? So you'll know where it starts, where it ends, and what happens in the middle in a way that it absolutely has to happen that way, regardless of how you get there (how many scenes it takes)? When you have that cohesive whole written down, then start chopping off/adding scenes to your heart's content. That way you can be a planner and a pantser, and you'll have your first draft written. I've started writing when I was 8 and I've never left a story unfinished. Of course none of that was usable in the future, but at least it taught me how to persevere from start to finish, no matter how crappy the middle. To this day, I think that there's nothing sadder than a story unfinished. I don't want to be dramatic here, but maybe it will help if you think that you can die tomorrow and someone will find your story unfinished and they'll never know how it ends. And maybe they're interested! So, at least, write it all, if only the bones of the story. You can add to it later. Sorry, didn't mean to be overly dramatic, but that's how it works for me. Hope some of this helps.
Thanks Rosacrvx, you're points are really helpful and no you're not been overly dramatic, you're absolutely right. I'm actually doing a little chapter 'outline', just listing my chapters with a short summary of what needs to happen in each one, it has helped a lot.