Will answer what I can:
4) In core, check user registration in Options.
5) I don't know how that work, but there is post ratings by Dark Immortal, which works fairly good
6) Q&A is the best core option, there are a few other resources as well. I use Are you a human by LukeGB
7) It is the default behaviour of xF. Staff posts don't have the no follow tag though
8) Tapatalk have an addon in the resource manager. There is also a mobile style
9) There are a few guides for that, one here: http://xenforo.com/community/resources/sub-nodes-in-columns.580/
10) Robbo has the profile completion addon that encourages user to go through certain steps after registering. Other than that, you can use notices and the notification addon by Chris. There are no way AFAIK to "force" them.
I tried finding some links, but I hate the search here on xF and I am kinda lazy....