Module development and code questions

I have donloaded a chat module from drupal.org.
To install it in the site I copied the .module file and its required directories to the module folder of drupal.
I have also added the chatbox.mysql to the database folder.
How can I make a user make use of that module? like to provide a link so that he can start chatting.
Or do I need to anything more to make the module work???

4.7.3. I am developing my first node type module and wish to display the categories side by side instead of vertically. I got this working by putting a function myTheme_taxonomy_term-select($form) in template.php in my theme folder.

I would prefer that this altered display applies only to my new module, not every usage of taxonomies.
My new module has two required vocabs but a "Page" node is likely to use only one. This breaks my current themeing, as it hard-wired to a two cell table to get the horizontal display.

I'd like to call a php function I've written upon each successful file upload. My function creates a thumbnail image from a video clip. I'm using CCK to define a custom content type which stores a video title, the video file, and a thumbnail image.

I've been reading the documentation, and scouring the drupal code. I believe the approach would be to alter the 'upload_nodeapi' function in some manner.

An alternative for the im 'instant messenger' (http://drupal.org/node/14553).

http://para.ro/project/messenger

I am creating a module for users to register for an organization, and am using profile.module as a reference, but I am not sure exactly how they are using hook_user(). In profile_user(), there is a switch statement that calls different other functions depending on the value of $type. These functions are profile_load_profile(), profile_form_profile(), profile_save_profile(), profile_view_profile(), profile_validate_profile(), and profile_categories(). Many of these functions are similar to hooks (such as hook_validate() and hook_form()).

In drupal can anyone tell me how to exclude a node type from the search indexing?

I have read that there is a way in 4.7. Can anyone tell me how? This would be for a custom module.

Thanks...