Content access management for groups

Hello,  i am just getting myself acqainted with this tool and had a few question which I hope you can clear.

1. Assigning content to groups is fine, but is there a 'general content' section that I can create which, by default, can be accessed by all groups? Or am i supposed to create content and manually give access to all of my groups?
2. Can we have certain compulsory and elective courses within groups, and also in the 'general content' section as previously mentioned? I understand that we can create rules in Storyline 360 by about users having to complete a set of compulsry scenes before accessing further scenes or content like quizzes etc. but I am seeking better clarity in this matter.
3. What are all the ways available on this tool regarding reminders? I would like to explore all possibilities - whether it is about annual reminders, reminders to complete a course, due date reminders, reminders for compulsory courses but not the elective ones etc.
4. It would be nice to have answer to this question asked by a member: Reach360 - Course Specific Learner Notification | Articulate - Community