General help

Hi Yann,

To answer step by step:
At the moment, when is open the gradebook for a course, all items in the course are added by default.... Where can I disable that, so I can create a gradebook with only custom items? You can hide individual items that you do not use. But what I do in my gradebooks is set up categories, or headings, under which I put the items according to whether or not they are included in the final grade or not.
How can I, As manager of a category, customize each student's report, aggregating student's grade for all courses inside a single report, including student's picture, and a custom field to be filled by the head of the school to add a general comment for the end of term report? This part, as far as I know, you can only do by linking courses together such that one course builds on the next. There is a great book on the Moodle Gradebook by Rebecca Barrington by PACKT Publishing. I would seriously suggest taking a look at that.
Once I have this custom gradebook created, how can I add it to each courses inside a category? As far as I know, there is no way to create a gradebook template which can then be added to other courses. That said, you can create a template course with the gradebook in it, and then copy that course however many times you want.