The plugin DigoWatchWP scans your blog posts and pages for changes.
Go back to you Plugins page, and click Deactivate for DigoWatchWP.
No problem. Go back to the Plugins page and click Activate for DigoWatchWP.
No, DigoWatchWP cannot prevent that somebody uses bugs in your WordPress-Blog. It will just notice, that something has happened and your posts/pages have been changed and will inform you via Email.
NO, you should always update your installation to the latest stable release as quick as possible.
Well WordPress is great software, but you never know - software tends to be buggy and so there could be an unknown bug in the latest release. So it is always good that someone has a look at your posts/pages - DigoWatchWP does this job for you.