Hi @waters,

This answer has two sections:

1) Disable register: just go to Users > Settings > Registration & Login > Default user permissions and set the parameter New users can register to: No (Only admins can create new users). That's it, no more register links because registration is disabled in the whole site.

2) Remove login link at the top bar (site skin): this is a bit more tricky because that black bar is a skin shared by all the collections of your site, so you basically need to override the default site skin by going to the skins_site folder and creating a new folder inside of it named custom. Then, locate the file skins_site/_site_body_header.inc.php and duplicate it into skins_site/custom. Finally, locate the following block of code in the recently copied file skins_site/custom/_site_body_header.inc.php (around line 157):

			// Login link:
			// Call widget directly (without container):
			skin_widget( array_merge( $right_menu_params, array(
				// CODE for the widget:
				'widget' => 'menu_link',
				// Optional display params
				'link_type' => 'login',
				'link_default_class' => 'swhead_item_login '.$right_menu_params['link_default_class']
			) ) );

and remove all of it.

That would do the trick.

More info about overriding site skin can be found here: http://b2evolution.net/man/custom-site-skin

Regards!