Module development and code questions

I've been successfully running Drupal 4.5.0 and decided to install Flexinode. I downloaded flexinode-5.4.0.tar.gz, unpacked it and moved the flexinode directory into the modules directory, per the install instructions. I then successfully ran flexinode.mysql and the database was updated. I then tried to go to the modules admin page and got this error:

Hey everyone, first time poster here. I ran across Drupal a few days ago and I've been plugging away at it almost non-stop so far. Then I found flexinode and thought all my dreams had been answered. :) But now I have a bit of a hang-up that I'm hoping I can get some help from.

I'm looking at doing flexinode relations. I've read all through this post: http://drupal.org/node/8468 - I've downloaded and tried to figure out how to use the new nodeselect field, but I'm not having any luck.

I'm developing an online quiz program. I'm debating whether I should roll my own or extend drupal to add this feature. Extending drupal is more attractive because alot of upfront work is done for me.

I have a hook_user function in my module, in which I create some fields with values. As a result this creates entries in the users table for the parameters created.

How do I delete these values from the database?

Is anyone working on updating project.module for Drupal 4.5? And what about the version of Project being used on drupal.org itself? And will there ever be a point where the system is customizable away from software releases and more towards general project use -- a website project doesn't need a license or patches for example.

How can I tell what the active node is, or more specifically what the category is of the active item? I tried a global $node, but it didn't seem to be available.

help!