Oh, come on...
as for 1, I don't know, ask the chatterblock author directly.
For 2.
Geeklog has a system default language, and optionaly a user language. if languages/userlanguage.php does not exist, the system falls over to languages/systemlanguage.php.
Plugins generaly use the following code;
$langfile = $_CONF['path'] . 'plugins/pluginname/language/' . $_CONF['language'] . '.php';
if (file_exists ($langfile)) {
require_once ($langfile);
} else {
require_once ($_CONF['path'] . 'plugins/pluginname/language/english.php');
}
So if the plugin doesn't have the language chosen, then it will fail over to the english. Note that $_CONF['language'] is set intellegently in lib-common.php, it defaults to the value in config.php, but, if the user has a language set that exists, it is changed to that. SO a system configured to run in german, with a user who asks for english $_CONF will say it's english by the time this code executes, unless english.php doesn't exist when it'll stay as german. If you follow.
So if you want to run your site in hebrew, and your plugins don't have a hebrew.php then you'll have to create one or the plugin will (likely) default to english instead.
Hope that helps.