>Why are there (personal?) email addresses in there as well? Who sets that as their user agent?

Might be some programming exercise. It's a common network programming exercise to build a HTTP client using bare sockets. But they don't look like student email addresses.

I think for respectful web scraping it is common/preferred etiquette to include some contact info.

Some APIs require contact info in the user agent header. For example, all calls to the reddit API are supposed to contain the dev’s reddit /u/username in the user agent.