You may get some of the way there with Profile:Edit or Zoo Visitor in that they abstract out member management to channel entries so you would be able to READ members from front-end templates using their module tags along with native EE channel entries tags.
You could possibly CREATE members from the front-end too if — in the case of Zoo Visitor for example — you set autologin="no"
. This should prevent the the person from being assigned a session ID and automatically being logged in as that user. You would need to ensure that you remove any {if logged_in}
checks in the template.
UPDATE would be possible if you pass in the member_id or the member_entry_id of the profile you wish to update as is the case with Zoo Visitor. Profile:Edit will only enable you to update the profile of the currently logged in member.
[EDIT 1: James (below) has mentioned that you can also pass in the member_id to Profile:Edit to allow you to edit a specific member profile and not just that of the current logged in user.]
As far as DELETE goes I don't think either module will provide a way to do this in the way that you're hoping from the front-end. Profile:Edit doesn't provide this option at all and whilst Zoo Visitor provide a delete tag it can only be used to delete the currently logged in member from the front-end for obvious reasons.
You should be able to achieve most of what you want to with both addons if used in the control panel however and being regular channel entries you can assign member groups with varying permissions along with custom member fields. This would be your easiest option but if working from the front-end is essential then it could be worth checking out Open API. It acts as a platform and doesn't provide a ready made solution as soon as you install it so you need to be prepared to get your hands a little dirty in getting in building a CRUD based member management system.
[EDIT 2: Although I've not used the module myself it seems that Solspace User has the ability to both UPDATE and DELETE users along with providing a means for a single Admin user to CREATE users from the front-end. Overall this seems to be your best bet in achieving what you're looking to do.]