You must be aware of this but here's who I consider ( to my knowledge ) to be at the forefront of those questions and the best documented / systematic and comprehensive resource ;

https://nickbostrom.com/existential/risks.html

As a side note, and from someone with negative karma, you may wish to peruse my recent comments about Covid, some seem to think they are unthinkable ideas while I persist in saying they are worth considering, although it is about an ongoing black swan and therefore probably not within the scope of your survey, they fit your description in that way.