I don't think they can get past that main node, China effectively filters whats its user can see and what's it user cannot but if there is some kind of encrypted connection , using TOR( which effectively routes different packets through different place) , then I guess the user can get past that firewall , because most of the filtering is automated. And I don't Chinese users can use 8.8.8.8 because it should be blocked.Blocking public DNS like that is very important to censorship.
I also guess PDF is not allowed there, the Chinese members here are Chinese government propagandists/ foreigner.