Figure it out AIOSEOP A-Z Optimizing All in One SEO Pack Forum

For what I've read this is a great tools and I also think it is, and after start installing it I have some issue that need some help because i'm not to familiar with WP things yet.

1. what is the use of "noindex" option at "noindex for archives/categories/etc"?
2. "autogenerate description" checkbox option, if I check it at the config form, should I no need to fill decription form in the
most below section of my post?
3. what is the use of "exclude pages", "additional post headers", "additional page header"?
4. and if I already use this AIOSEOP, should I still need to fill post tags at my post?

Sorry for asking lots of question, coz i'm still trying to understand its functionality..and maybe can You refer me a brief documentation or video tutorial would really help :)

and last question, 5. if I buy a pro one, can I use it to deploy to many WP site, as I'm planning to have WP site services around neighbourhood here. Thanks alot and appreciate much for the answer.