@bangskij It should allow you to paste a URL you want to be crawled. (Careful with the depth setting! Something like 12 or 18 will crawl the whole internet...) Also, when I tried it, there was a proxy function. Set your browser to use the YaCy proxy and it will crawl all sites you visit.
@datenritter I managed to open the port, connect properly to the network and get a crawl starting. It's using very little bandwidth, about 1-2 megabits with the odd spike into 10. Considering I have a thousand of those and use them for email and this social network I think I should be good. It still posts an error message but it is also crawling so, guess it's fine. I don't know how to proxy my browser through it though but it's late here, try again tomorrow.