CP Logging logs both Admin and Moderator activities, mostly deletions and the like; we're pushing to have it so that if anything affects forum content that it get logged. A lot of improvements are coming in 7.2 however, namely being able to store the content in the mysql database vs flatfiles which extend the ability to store more information.
And the only way to view the log is not to download it, when you login to the control panel you'll see a link to the right stating the log size, if you click on it it will let you browse the logs via the web browser.
