Editing WordPress Admin Post Pages

Hi, I have a very specific question here and was wondering if it’s implementation is possible. The reasons are I am looking to automate my website as much as possible and maximise wordpress possiblities as a CMS.

1. When i click the “Write Post” tab, it will come up with a screen asking what Category the post will be in.
Then dependant upon the category i click the post screen will be displayed with some data already filled in e.g the Key’s for the Custom Fields.

2. Also is it possible to make fields automatically update. For example as I am typing in the tags for a post, the same words will be entered into the keywords field automatically?

I really would be greatful if anybody could help on any of the 2 queries.