Search functionality is provided by MySQL full-text searching. This is a natural language search that allows you to type in a question or regular sentence that describes the information you are looking for, and then uses programmed logic to determine the keywords in the sentence. See here for details Boolean Full-Text Searches.

The minimum and maximum lengths of words to be indexed are defined by the ft_min_word_len and ft_max_word_len system variables.
How to change ft_min_word_len 
Fine-Tuning MySQL Full-Text Search
Full-Text Stopwords

To translate to other language you should copy directory kb/admin/lang/en and rename 'en' to translated language.
Made all necessary changes in .ini files and in config_lang.php
Set your language in $conf['lang'] variable in admin/config.inc.php
($conf['lang'] = 'your_language_folder_name';)

We have made some special utilities, it will display some help information:

• http://your_domain.com/kb/admin/lang/test_language.php
• http://your_domain.com/kb/admin/lang/display_language.php

You can find available localizations in download section.

Instructions can be found in this article.

For now so called "Search engine friendly URL" works only on Apache web server.
It should work automatically if your Apache is installed with mod_rewrite enabled.
Please read here for more details

Sure you can. The process is like for adding image to article. Use "Insert/Edit Flash" or "Insert/Edit Link" button from FCK editor toolbar.
Tip: you can add any HTML inside the content page.

No. Currently KBPublisher supports only MySQL.

MySQL is not enabled by default, nor is the MySQL library bundled with PHP. In order to have these functions available, you must compile PHP with MySQL support.
PHP manual - MySQL

Set conf['debug_info'] = 1 in your_kb_installation_directory/admin/config.inc.php. It will  display  an error if  you do not have MySQL extension enabled.

It means that server is unable to send an email.
You have to set up correct email settings under "Settings->Email" menu in Admin Area.

Normally it means database error.
To see more descriptive message, set $conf['debug_db_error'] = 2, at admin/config.inc.php file

The most likely cause is that your PHP installation does not have GD. Check if the GD library is installed with php and install it if it is not.
Information about GD and instructions for installing it can be found on the PHP site at http://www.php.net/gd. 

Hits/downloads updated daily by scheduled task (cron).

There are two settings:

1. Settings -> Admin -> Session expires (in minutes) - for Admin Area 
2. Settings -> Knowledgebase -> Session expires (in minutes) - for Public Area

Set it to the required value in minutes.
If you don't want the session to timeout at all, set these values to 0.  Your session should remain valid until you close your browser.

If it does not work as expected check the following values in your php settings.

1. session.cookie_lifetime (Default: 0)
   - session.cookie_lifetime specifies the lifetime of the cookie in seconds which is sent to the browser.
   - a value of 0 means "until the browser is closed"
2. session.gc_maxlifetime (Default: 1440)
   - session.gc_maxlifetime specifies the number of seconds after which data will be seen as 'garbage' and cleaned up.
   - garbage collection occurs during session start.

Tip:

• Do not forget to restart web server if you change php settings.