for normal user accounts - no problem. For users with adminCount=1
Sorry for the confusion, but we are not sure what exactly the issue is at the moment. Do you still face error messages when deleting user accounts? If that is correct, please, post here or send us (support[at]adaxes.com) a screenshot of the error message and specify how exactly you attempt to delete users.
Grant the Adaxes service account permissions on all accounts affected by AdminSDHolder
It is not required and moreover will not work as all Ad related operations in a managed domain are performed with the credential of the account used to register the domain in Adaxes. The Adaxes service account (specified during Adaxes installation) is not used.