I'm writing a novel, and one of my characters is into some illegal activities on the web. He's ultra-paranoid about security, so uses Tor...but he doesn't want anyone who might snoop in his computer files to know he's installed the Tor browser. So here's my question: On a PC, can the Tor program folder be placed in a file-security app like Folder Lock, or does it need to stay in the Program Files folder? Thanks so much!
Yes, this is possible. As said in the comments, Tor can be run from pretty much everywhere.
Tor Browser can be used as a so-called portable app. This means you download the software and extract it. You can extract the software basically to any folder, device, etc. So some people use it on a USB stick or put it into their local folder. You can simply click on start Tor Browser and the software starts.
The answers to the question »Are browsing files stored locally?« describe that Tor tries to not write any files to the local drive. So also the fact that Tor is used is quite hidden.