You can browse the forum and visit the registration form, which does not seem to block. I think it's allowed

Problem with Tor and IP2 is that onion routing in a low-latency node based network is a fundamentally flawed concept. If you want anonymity against the feds, we will need a different conceptual design.
The way TOR is constructed is indeed drawing attention. I think, in order to have anonymity, a new conceptual design is needed as you mentioned.