If you show us an example it would be helpful to give you more accurate info.
If you mean having the same site on few domain names, then they will be considered duplicated sites and your websites will be banned.
Heard about it few years ago, I never used it though.
That would be Yahoo.
Google is a good search engines, I personally always use it.
As long as you submit your website to quality directories, then your website will benefit from these links. The same applies to directories...
Page rank depends mainly on the amount and quality of back links pointing to your website and the page rank of the websites your getting back...
Xenforo takes my vote, many forums are now moving from vBulletin to Xenforo.
The code you have used will deindex all of your website pages, fodlers, etc, so what you did is not ok. Also, your robots.txt file should be in...
If the website you have used to build back link from are not related or not strong and trusted websites, then it will not help you much in...
From your list, I would go for .org.
Good off page optimization, original content and quality relevant back links.
You can build some back links for some of the pages, it will help index these pages with other pages.
Separate names with a comma.
