it's best to bring up these concerns at vbulletin.com
1. Are you sure about that, it's been a few years since I resisted on vb.com or .org, but this info is posted at the .com
2. That question belongs at the .com
3. What part do you need help with, there are several pages of info on
backing up your forum in the docs.
4. That question belongs at the .com
5.
http://www.vbulletin.com/docs/html/stylevars_intro
6. Why would it show that, it's up to the user to find out which plugins they would want, doing a google search will find several opinions on
what plugins to use. vBulletin.com will never suggest plugins, they are in business to make sure the core product works as described, you can find the plugins you want here at the org.
Please be patient, you said you've only messed with it for 2 hours, vBulletin is great but can't be learned in an afternoon