very dystopian future... the principle of protection of human autonomy was tossed away already when they legalize 'non consensual' anything
Non-consensual conversation is legal and socially approved. A society where non-consensual anything is illegal would look very interesting - explicit mentions of kind of interaction you're open to, long escalation of extremely subtle signals, people mostly ignoring each other all the time, ubiquitous go-betweens - but hardly the only non-dystopian one.
have massively different neural wirings
Meh. There are some differences, but not nearly as big as between two random minds.
That we see gross modification of existing individuals as death
Yes, but it's not that huge. It's a rather isolated preference change.
The 30x thought speed advantage won't save them.
They're entirely toothless however, with no concept of biting and no carapace.
Can't see why. They understand treating language as a vending machine - vibrations go in, behaviors come out. The sounds "r-i-ch-b-a-n-k-er" need not be evidence of a person's finances. They didn't evolve for the same kinds of competition, but they have a concept of non-truthtelling. So I don't understand where you're coming from here.
Non-consensual conversation is legal and socially approved.
The story is speaking of "non-consensual sex", the illegal kind (rape), that was legalized. Great many actions are deemed illegal without consent as to protect autonomy of humans from other humans; when you start legalizing those actions, you drop off the autonomy. Especially major things.
Conversation is not illegal and thus can't be "legalized". Also, try having conversation with someone against their will, or when they are obviously busy. It is deemed impolite, and is not...
"The kind of classic fifties-era first-contact story that Jonathan Swift might have written, if Jonathan Swift had had a background in game theory."
-- (Hugo nominee) Peter Watts, "In Praise of Baby-Eating"
Three Worlds Collide is a story I wrote to illustrate some points on naturalistic metaethics and diverse other issues of rational conduct. It grew, as such things do, into a small novella. On publication, it proved widely popular and widely criticized. Be warned that the story, as it wrote itself, ended up containing some profanity and PG-13 content.
PDF version here.