“Allow not super administrators to create, edit and delete users” option is aimed for the single site admin (user with ‘administrator’ role but without ‘Super admin’ privilege) and help to work with WordPress users. In order to manage BuddyPress members and groups at a selected single site user should have ‘manage_options’ capability. This definitely gives him an access to a lot of other staff.

You can block access to unneeded menus using “Admin menu access” add-on.

Just be accurate with “Block not selected” model there as it’s too restrictive and some functionality could by limited unintentionally. It blocks any link from left side admin menu, which is not directly selected at the menu items list. This includes the links which may differ just by parameters inside the same link.