Hello Emphatic,
1) Unanswered questions are marked as "Not answered", not wrong.
2) You can configure the quiz to display the results immediately or a later time.
3) You can easily define separate course categories for each branch.
4) Login information can be sent to users: https://docs.moodle.org/38/en/Accounts_FAQ#Can_Moodle_send_a_notification_e-mail_automatically_to_a_new_user_when_an_account_is_created_for_them.3F