Hi, I would love to know if you can raise and lower the reputation of other users and how, thanks!
You mean besides upvoting/downvoting their posts?
You might want to look at some of the plugins listed in this topic to see if any do what you want.
I'm looking to be able to see a report that shows the top Topic starters and posters over the previous X number of days. Is this possible?
req.user is set on login.
I'm don't know, i've only worked with 0.7 version. Are you sure there is such option in 0.6? If so, maybe this is template error
NodeBB core doesn't have anything to prevent this. But plugins can be made to prevent multiple accounts from the same IP etc although it can be easily by passed.