Module development and code questions

i have recently upgraded my drupal 4.7 to druapl 5.0 and installed the google sitemaps (XML sitemaps) module (http://drupal.org/project/gsitemap) the sitemap is not being generated now and when i open the sitemap url of my site it says

Error loading stylesheet: An XSLT stylesheet does not have an XML mimetype:http://www.siddharthfans.com/sites/all/modules/gsitemap/gss.xsl

I want to write a module wich meet this requirement :
- There is a select box include some items ( I've done it already).
- When i select an item in select box . It will change a variable "choice",which is a global variable.
I'm so new to drupal that i don't know how to do it.
Thanks for your supporting.

i'm building a health website. a service will be to online bookkeeping of users' various records. is there a module to do this?
thanks,
erick

i have a community. can flickr module support each user to have one or several their own photo sets from their own flickr.com accounts?
thanks,
erick

I'm wondering if theres a way to hook into the Drupal user registration process in such a way I can affect the process itself. Here's basically what I'm trying to do:

I'm building a World of Warcraft guild website, and I've decided to take my time and create some custom modules that interact with the games resources. I'm attempting to make them generic and configurable enough that I can post them here as modules available for the public. The module I'm working on now I want to hook into the user registration process so when a user signs up, it connects to a service called the World of Warcraft Armory to verify the username they are signing up with actually belongs to the Guild the website is for.

In my example, say my character's name is "Toblerone" and I'm in the guild "Mechanical Squirrels" on the server "Skywall." The World of Warcraft Armory allows me to type in that character name Toblerone, select the server Skywall, and it will tell me the guild he belongs to, in this case Mechanical Squirrels. I want my module to connect via cURL, or just plain old sockets to the Armory site, grab that XML data, verify that when Toblerone signs up for the Mechanical Squirrels website, he's in the guild Mechanical Squirrels.

We are using the refine_by_taxo module on our site.

It works great, except that on some pages it only shows the first 3 taxonomy terms for the listed content and it seems to ignore the rest.

I have tried changing the settings for the block but nothing seems to work.

Any ideas?

Thanks