The Foxtor plugin requires that you run both tor and privoxy. Parts of its proxy checking scheme are also questionable.

Just use FoxyProxy. As long as you check the box that says Use SOCKS proxy for DNS lookups, it is just as safe as running Tor through privoxy, without the added overhead.

The qualm Blackstone mentions about the terminal tor server* potentially revealing details to a spy is basically a problem for military or famous people who use Tor for unencrypted email, and insert sensitive or identifying information into the mail. Since anyone using Tor to post here would be posting the message openly anyways, no hazard arises from the administrator of the 4th tor server being able to read the same info off his/her own computer.

My point was that you shouldn't be doing things like checking your web based email or doing online banking with tor on. Unless the email is encrypted from end to end, whoever runs the tor exit node can read it. It's important to be aware of the limitations of tor. Tor provides excellent anonymity but no confidentiality.

Even using https is not 100% safe with tor since the tor network is one of the only places where a rare man in the middle attack has been observed occuring in the wild.

My advice? Use it only for visiting BL related web sites and turn it off as soon as you are done.