We don't randomly display errors. The errors you may see (522, etc.) are the result of our not being able to connect to your server & that's why the error messages occur. The bulk of the issues we see support side from the client's actual server are:
503s
Empty reply from server
We should not affect your traffic, really. If you're using some sort of tool that requires original visitor IP, it may be thrown off until you install a mod to restore visitor IPs (our ips are going to show until you do).
Any customer that has a site issue should contact support with any offline issues. We're more than happy to take a look and share logs with what we're seeing trying to connect to the server for the site.