Module development and code questions

hello,

i want to make a site for my wife where she can offer drawing of babies from their digital portraits, uploaded to the site.

i want to use ecommerce since she will later sell some of her artworks.

is this possible to do the following use-case with drupal+ecommerce:

When I create a page in a module, I usually define the page title in hook_menu like this:

$items[] = array(
'path' => 'contact/address/add',
'title' => 'add an address',
'callback' => 'address_add',
'type' => MENU_CALLBACK);

However, is there a way to define the page title somewhere else?

Let's say I have this:

Hello all.
I want to know how a module ca interact with the core profile module : need to creat custom fields, ability to display some other fields for a user. thanks.

In my project I need allow the visitor to create a node type content and then store the node with 'uid = 0'. Then I will ask the visitor to login or even register before login. After the user login Drupal will set the uid to this user's id.

How can I do it?

Not sure where to go with this perhaps someone could help me.. I have been spending many hours and now a day searching patching trying to figure out why after you enable the subproducts.module and apparel. Module, I am unable to add any other type of product other than apparel.. For instance if these two modules are enabled at the same time I can not create a tangible product, shippable product or another kind of product other than apparel product.

I am planning to write a set of modules to manage a sports club. This includes regulations, teams, rosters, schedules, standings, statistics, etc.

The outline of the modules stands, but before I start coding I would like to know if someone knows of other modules or other CMS systems which handle this stuff. I dont need to do it again if it is alredy done.

Also I wanted to ask if someone is interested in helping. The modules could be hosted at drupal.org for collaborative developement. If you have any comments (especially to the posted plan) feel free to share it!