Banner management for Wordpress site

Using Wordpress Background: I have a website which is nearly finished. The site is using Wordpress. I have structured the site using Wordpress pages. The Post Categories mirror that page structure. The site looks a bit of a mess and is difficult to navigate. Project: 1. I need it set up so that when I'm looking at a page, it displays all the posts from the corresponding category (from category name that matches the page name). 2. I want child pages of the current page to be listed on the right hand side as links similar in style to recent posts or other articles. Titled: pages in [[Parent Page Name]] 3. I want sibling pages f the current page to be displayed on the right hand side as links similar in style to recent posts or other articles (Siblings will be pages on the same level/ pages with the same parent). Titled: Pages in [[Page Name]] 4. I need is a system where I add banners (I have already installed Adrotate which is doing the uploading banners bit) then assign banners to MULITPLE PAGES. Then when the page (or corresponding category) is viewed the correct banners are shown. If I assign a banner to a parent page, it becomes the default for all child pages, unless I assign a different one to a page lower down. The site is on [login to view URL] Please tell me how you can impliment this and how you can improve the style of the site. Please confirm that you will not loose any existing functionality or plugins.