Module development and code questions

ip locator

1. investigates an ip address and/or domain name
2. shows to your visitors their country location
3. ipl_country API function returns visitor's country information
4. the ip_locator_nodeapi hook is implemented. $node->ipl_country_code, $node->ipl_country, $node->ipl_country_flag node object members are available for theme engines
5. the ip_locator_comment_load API function is similar to the ip_locator_nodeapi, but it works for comments

I'm creating my own node type based loosely on the book module. Was wondering if anyone can point me in the direction of how to go about so that, given a text, I can post-process the text and create the tree structure of the book and the content of this tree using something like regular expressions within the text.

Eg:

A story
=
Chapter 1.
==
page 1
==
page 2
=
chapter 2.

where '=' might be taken as the first level nodes in the book and '==' as the second level nodes.....

This has little to do with drupal, but, the system is based on drupal. What is the limit of directories? Can I make a million of directories within the files directory?

I want to do this:
When someone uploads an image for node number 123, I will create a directory for that node in files and save that image in that directory. The directory will be: files/123/myimage.jpg.

What if the site will have 20,000 nodes? Will I experience problems? Should I redesign this strategy?

Thanks

Are there any plans to integrate auto-complete feature for textareas?

What I mean is auto-complete word by word while typing content to
textareas (when editing/creating nodes). I know that auto-complete is
already available for textfields in the core. What other possibility do I
have to add this feature. Any AJAX-framework supporting this?

I'm working on using ldap_integration and have run into a couple of problems. For some reason, I am not able to use TLS encrypted connections to communicate with my LDAP server(eDirectory 8.7.3). Cleartext does work though.

After doing some research, it has been pointed out that a possible cause is this:

"The LDAP client does not trust the Certificate Authority that signed the LDAP Server's certificate. Typically, each LDAP client keeps a list of all the Certificate Authorities that it trusts. If the CA has been recreated, the LDAP client must update its list."

I've created an administration module to browse, edit, delete and chmod files on the server and would like to contribute it to Drupal's modules list. I do searching the whole site with several keywords but found nothing about how to do that. I do create a project using create content menu but nothing happends. Anybody here could give me some hint on how to do this, please?