OK, my assumptions here are that you are new to using a Learning Management System and don't know much, if anything, about Moodle. Also, your use of terms like Batches or Sets, Sessions, be careful with them in Moodle, they may mean something different and are likely to cause confusion if you and whoever responds don't quite see them in the same way. I'll try not to confuse them, but don't be shy in asking questions.
1. An LMS is about breaking degree courses down into individual subjects, and each subject into individual topics. A three year degree will have 6 semesters. Each student has to complete, say, equal to three semester long subjects each semester. Some semester long subject have six topics, some have three, The LMS provides a framework to offer that learning to anyone enrolled in that semester long subject.
2. Overview of student achievement tracking is provided to the institutes Student Information System, via a report from the LMS. These are two very different and separate systems. Any system that suggests it is both is bloatware and prone to frequent crashing. These are usually very expensive, have excellent sales departments and normally provide little real support, unless you pay for it in which case, support is minimal. At the end of their studies, the SIS confirms they have met all the minimum requirements and awards are granted. Records are then archived in the SIS.
3. Students can be enrolled in a topic/course easily, complete the work, and the course can be reset to accept the next block of students. Before a topic/course is reset, it is backed up showing actual student achievement, complete with all data and information that is uploaded by student, all grades and comments by lecturers, graders, everything, and that is archived. If your storage medium is well organized, well maintained, and updated when systems change, you should have access to student records going back decades, eventually.
4. Moodle has a structure that starts with the Front Page, then it has Category pages where overarching groups are made, e.g Maths, Science, Philosophy, Underwater Basket Weaving. Each Category can have a set of sub-Categories, say Year 1, Year 2, Year 3, Year 4 topics, Underwater Basket Weaving Year 1 has two half semester 1 long topics, Breathing in water and Avoiding Sharks, and semester 2 has 1 topic, selection of weaving stocks - and so on through three years. Students are enrolled in each semester course, and if they drop a subject, they are not enrolled. The SIS tells the people responsible for enrolling students in topics/courses and the students have access to the right materials.
5. The either complete or don't. In either case, they are no longer enrolled in courses so can't access anything. What actual rules and practices you put in place here is up to you.
Clearly, in reality, this is a lot more complex than I suggest, but this is just brief descriptions of what can be done.
My first recommendation though is to download and setup a Moodle, then use it, play with it, see what you can do with it. If you want a quicker introduction to how to use Moodle, have a look at MoodleCloud. Sign up and play, it's free and actually useful.