Profile Options
Suggestions
If an admin makes a profile 'inactive' none of their content will show on the site (although it still will be there).
If a profile is deleted, all their content is also deleted.
There is an admin option to allow members to 'self-delete' their profile. By default, it is disabled. I recommend leaving it like this then if a member want to leave your site they need to apply. You can then transfer ownership of any of their content if you want to keep it (install the free 'jrChangeOwner' module to do this) prior to deleting them.
hth
updated by @paul: 10/06/15 09:32:38AM