Here's my attempt to translate these lessons for folks who worry about foom:

(a) Taboo informal discussions of powerful AI and/or implications of such. If you can't discuss it in math terms, it's probably not worth discussing.

I'm not sure how this follows from the previous lesson. Analysing the impact of a new technology seems mostly distinct from the research needed to develop it.

For example, suppose somebody looked at progress in chemistry and declared that soon the dreams of alchemy will be realized and we'd be able to easily synthesize any element we wanted out of any other. I'd call this a similar error to the one made by the Dartmouth group, but I don't think it then follows that we can't discuss what the impacts would be of being able to easily synthesize any element out of any other.

It might be good advice nonetheless, but I don't think it follows from the lesson.