"There is a separate, more experimental, build available that supports HTTP/2 draft-12 for http:// URIs using Alternate-Services (-01) and the "h2-12" profile. Sometimes this is known as opportunistic encryption. This allows HTTP/2 over TLS for http:// URIs in some cases without verification of the SSL certificate. It also allows spdy/3 and spdy/3.1 for http:// URIs using the same mechanism. "
You are misunderstanding. The requirement for CA-issued certificates and most of the other things you are ranting about will still be only for HTTPS, which will still be optional. HTTP URIs in HTTP/2 will only need self-signed certificates which can be generated automatically by the server. Once servers get good support for it will not be any harder than HTTP/1.1.
As for physics, you are mistaken. The only kind of "time travel" that has any basis in physics is the one using Closed Timelike Curves (which is what the article is about) and those are limited to the time the CTC was created in the past.
So, in fact, this is a very good reason to reject the argument of "If it is possible, where are the time travelers?".
No. They may do that now but the intention is to support HTTP URIs that force TLS but allow self-signed certificates.
See https://wiki.mozilla.org/Networking/http2
"There is a separate, more experimental, build available that supports HTTP/2 draft-12 for http:// URIs using Alternate-Services (-01) and the "h2-12" profile. Sometimes this is known as opportunistic encryption. This allows HTTP/2 over TLS for http:// URIs in some cases without verification of the SSL certificate. It also allows spdy/3 and spdy/3.1 for http:// URIs using the same mechanism. "