"Rather than seeking the elusive definition of what is a type (which does not exist), I believe that we should look for innovative ways to think about and work with types that do not require an exact formal definition."
So he doesn't want to stop at your point 1, but rather wants to find generalizations that apply to the commonality between these variations.
No. There may be some magic formal definition that would work between contexts. Until we have such a definition, though, he says it's better (at least between contexts) to work off of an informal, inexact definition, and to be aware that you are doing so.
"Rather than seeking the elusive definition of what is a type (which does not exist), I believe that we should look for innovative ways to think about and work with types that do not require an exact formal definition."
So he doesn't want to stop at your point 1, but rather wants to find generalizations that apply to the commonality between these variations.