Drupal 7.x

Hello, I have recently jumped into the Drupal learning curve and I am struggling a bit with the concept of creating a module the "right way". I hope someone experienced would be able to give me the right direction.

I was told that using CCK to create a module would gain me more benefits (use of views, easier updates, etc.) as opposite to creating my content type manually by storing all the info in one single database table (CCK db tables span disscussion.

I have just started using Drupal. Grateful for any help. I am not an engineer and hence finding the going tough.
I have about 20 pages of web site content that is already written in HTML. I cut and paste into the Drupal WYSIWYG editor and store the files and everything works fine.

I want to change the righs of an user as admin -- but dont find where to do this. The admin section of drupal is a mess, one dont find nothing

I'm trying to simply get feed items from an aggregator feed which is set up and has items populated. My Aggregator module is enabled. Other Aggregator functions seem to work. The aggregator_feed_load($account->series->fid) function directly above it works fine.

Is there something I need to switch on or something? is this a bug?

Can somebody give me a clear explanation as to when it best to use a shared field versus when to (create a content type and) use a node reference to relate content? I've gone 'round and 'round and can't tease out any advantage or disadvantage.

I'm wondering which of the following theme / block arrangements would cause the least amount of server strain:

1. Using a 4-5 block arrangement with a few conditional 'show/hide' block rules in conjunction with 5 different themes assigned to different site sections.

2. Using 4-5 block arrangement with around 100 conditional 'show/hide' block rules in conjunction with 1 theme.