Wordpress knowledegebase

Would like to use wordpress as a knowledgebase for a small business. Owner has basic knowledge of word press (is able to post content and assign to categories) Employess must be able to quickly search adn grab information they need in a quick customer service environment. Please read brief carefully as these inclusions (unless developer has a suggested better way of doing this) are to be included: I - Set up of wordpress site and settings - set up of master categories, subcategories and grandchildren categories (where applicable) - create a secure site, according to australian standards - and/or provide guidance in this area - website is private and not searchable - secure log in for all users -Entire site is private and cannot be viewed publically -Plugins used are to be reliable and stable - Set up of inital users (approx 6) and assign read/write capabilites - plugin used must allow for owner to easily add and remove users - Search function - very important - must have robust search function, so that user can very easily search for all related content under keywords -Back up - show owner how to back up site so no content is lost (preferrably in a MS word format) -Provide advice to owner on how to best maximise internal search capabilities whenevr posting content so that people can easily find information -after log in a page of call to action buttons with each of the categories (Allow for approx 15 main top categories) are in easy view of the user, where they click on each call to action button to then go to a page with subcategories. however owner is open for suggstions by developer on best way to present this information so that users can find information very easly - side bars - suggesting 2 side bars, with recent posts, category tree, search function, poll, submit query (for internal questions) and reference quides - each post has related comments, related posts and any other related content - set up of main pages; practice calendar, categories (allow for 5) -provide advice on hosting requirements, especially as the aim is to have instructional videos (not youtube).