The second issue seems more like something that could become a feature request than a concrete proposal. Consider leaving a comment in the issue with your proposal.
In EE there is a nightly LDAP sync worker that will auto-block any LDAP users that are no longer in the directory. This should address the active user count issue for licensing.
Large commits can't be viewed:
https://gitlab.com/gitlab-org/gitlab-ce/issues/10785
Users created via LDAP login continue to count towards the user-count even if the LDAP account is deleted:
https://gitlab.com/gitlab-org/gitlab-ce/issues/11844