Change WordPress user roles and capabilities › Forums › How to or FAQ › How to block menu items to all sites (multisite) ? › Reply To: How to block menu items to all sites (multisite) ?
I never saw ‘Delete Site” item at the admin menu. So I suppose that it was added by some plugin. Is it right?
Your assumption about a source of this problem is correct – URE works with admin menu copy from the main site.
There is no ‘delete_sites’ capability. Try to revoke ‘manage_sites’ capability from the role. May be it will help.