the rate of youth suicides haven't [sic] gone up
I cannot find a reliable recent source on this. However, older data suggests that the suicide rates for older people has been going down, but there is an uptick in rates for younger people. For instance, see Suicide rates by age from American Foundation for Suicide Prevention (based on CDC figures)
... anthropogenic global warming is not a grave threat to the planet and that climate change is being used as a scare tactic
Sure, in overall terms, global warming is not a grave threat to the planet. It is probably only slightly more dangerous than a catastrophic meteor impact. Apart from some coastal areas, the fundamental shape of the continents will remain pretty much in place. If you do not care that most current animal species (including our own) will not be part of the picture, there is really nothing to worry about.
Using the WayBackMacine to archive the site is risky. Recognize that one line added to the robots.txt at any point in the future can render all the content inaccessible (at least) and possibly cause it to be deleted.
I am quite surprised IBM, Microsoft, Google or one of the other big organizations has not picked this up.
Wouldn't it be easier to filter outbound packets destined for Gmail's SMTP servers and prevent Chinese email users from sending email to Gmail users? (This is an honest question.)
I think you mean Google's MX servers (the remote end when sending email through SMTP). If so, in a word, "yes", much easier, assuming users are using SMTP servers based in China. Indeed, you could simply prevent the connections from ever taking place, simulating authentication errors.
Since SMTP allows forwarding by other servers this would require deep packet inspection.
If you mean the SMTP protocol supports chained delivery routes, then I do not think this is true (at least not used in practice). However, business customers of Gmail (at least) can request that a different SMTP server than Google's be used for outgoing mail, and (of course) anyone using an external mail client can send using any SMTP server they like.