Mary Cooch

You use the jump to next page within an individual lesson to move from different pages/questions in there. From one lesson to another you would use  a different system - the prerequisite for example.

Thanks - just added to Upgrading FAQ

You can't do this in standard Moodle. You can set it so that users can only access courses within their department (category) through enrolment methods - for example either manually enrolling them to the relevant category or allowing self enrolment with a key which you only give to those in that category (department) or by using Cohorts. I am not sure you can easily add a different front page for each group however. There are other options based on Moodle and freely available for example http://www.iomad.org/what-is-iomad/ or ELIS

Yes  Or if you think you will add more documentation in future, you could add it to a dynamic page such as Google drive for example and then the link can stay the same -eg Arabic documentation - and you can add more translations later. 

Are you talking about the course as a whole or the lesson module (which you are posting to)? In the lesson you can add questions at any time. In the course you could use conditional activities and activity completion and half way through the course you could add a quiz with only one question and students cannot move on to the next activity until they have answered it correctly.