Agree with (1) and (2). I am ambivalent RE (3) and the replaceability arguments. RE (4): I largely agree, but I think the norm should be “let’s try to do less ambitious stuff properly” rather than “let’s try to do the most ambitious stuff we can, and then try and figure out how to do it as safely as possible as a secondary objective”.
(A very quick response):
Agree with (1) and (2).
I am ambivalent RE (3) and the replaceability arguments.
RE (4): I largely agree, but I think the norm should be “let’s try to do less ambitious stuff properly” rather than “let’s try to do the most ambitious stuff we can, and then try and figure out how to do it as safely as possible as a secondary objective”.