Im making somthing, and have a few neb questions.

First off, I need to find witch file creates a new user in the DB.
Second, how to not require so much information, I belive I will have to use a modified version of the non member ordering mod to do this.
I dont really need the address information untill they attempt to pay for somthing.
asking that much information can be a big deterant.
third, I need to force something onto a users cart.
EX:
a cronjob that reads the ebay API(witch is another project im working on alltogether)
finds the winning bidder for products, returns the email address and the item name.
it then makes a user with JUST the username and creates a password. Then adds the Ebay Item to the users cart, and CANNOT be removed untill after payment.
The winning bidder gets a email that says enter your email address and this PW to complete payment. Goes to my site, finds the item allready on the cart, and goes through my suggestion selling process.
Also pulls them off ebay when wanting to buy items.

I have a few other things to do, and this is a over simplification of the project at hand but a good outline.

any help?