JAR-FCL doesn't seem very precise in defining a syllabus for this purpose.
That is why JAR-FCL requires an Approved FTO to have a Training Manual that describes the course to be taught at that FTO. Does your FTO not have such a manual? This applies to all JAA training not just FI Courses.
for the 5 hours of mutual flying with another FI student: Does JAR-FCL prohibit flying into another country on a long crosscountry
The content of the course has to be approved; I can't imagine that any FIC instructor would plan a course like this and no competent authority would approve it. The purpose of mutual flying is to allow the student FI to practice the skills just learned with another trainee. Typically, a mutual flight should last 30 -45 minutes whilst you run through a typical PPL training exercise. There is nothing to be gained doing long cross country flights; in fact it would be a total waste of valuable time.
In my experience of teaching on a FIC it takes 20 hours to get to circuit flying which doesn't leave much time to cover all of the more advanced stuff.