Hello,
1. Yes in the idea only one-way communication mentioned, but of course it would be great to use its two-way advantages for e.g.: late ACK purposes. And yes it is another protocol on which syslog-ng could send messages. As faxmodem mentioned, with websocket it is possible to implement pub-sub communication which is also give us some new opportunities.
2. The webserver can be in any language. Theroretically python -m SimpleHTTPServer is perfectly enough to serve a static index.html cause js natively can handle websocket communication. This purpose is to shows that the destination is working properly. But if it does anything usefull like that you mentioned it is a plus.
By the way destination is perfectly cool GSoC project, but it would be great if the student implement the source or began to implement it. The reason behind this idea is that, one of the used protocol in IoT world is websocket (beside mqtt), so the devices could send logs directly to a syslog-ng server.
Best regards,
Laci