I agree with Marji that what you're asking is really so detailed and complex that you'd probably do much better to find a book that would lead you through the process.
If you've done a lot of sewing, you should be aware of the various pattern shapes that are generally used to make the silhouettes you're looking for. That will help you a lot. If you have access to Burda WOF magazines it can be instructive to look at the styles and then study the shapes of the pattern pieces shown in the layouts for those styles. You can do this with any brand of pattern, but since you mentioned language, I thought perhaps Burda might be more available to you than others.
There's a lot of difference between a sloper that is made to your measurements, and is a basic, close-fitting garment, and a design which you might create starting with that sloper, and there are lots of things like unstitched darts or darts incorporated into seams that can make it a little hard to tell just how you should go about creating a design by just looking at a finished garment. That's where some experience helps, but it's not infallible either and sometimes you just have to decide what you think will work and try it.
I think the best thing for you to do is to work through the exercises in either the Pepin book you've found online, which is a good one, or some other pattern drafting book. It's very important to do things step-by-step and in the correct order when doing pattern manipulation or drafting, and the best way to learn is to just do it. You can use 1/4-sized patterns to practice, and you may be surprised by how clear things seem once you see it in front of you and do it yourself.
This isn't meant to put you off and ignore your questions, which are good ones, but rather comprehensive in their scope.
Please don't hesitate to ask questions, and I hope someone here will be able to answer you on specific points.