Do you think these points make Europe/the EU more important than the US or China? Otherwise, they don’t give a reason for focusing on the Europe/the EU over these countries to the extent that this focus is mutually exclusive, which it is to some extent (e.g., you either set up your think tank in Washington DC or Brussels, you either analyze the EU policy-making process or the US one).
Reasons to focus on the EU/Europe over these countries are in my opinion:
personal fit/comparative advantage
diminishing returns for additional people to focus on the US/China (should have noted this in the OP)
threshold effects
This introduction might in some ways be more accessible: S-risks: Why they are the worst existential risks, and how to prevent them (EAG Boston 2017)