Since utility functions are only unique up to affine transformation, I don't know what to make of this comment. Do you have some sort of canonical representation in mind or something?

-1jsteinhardt6yYes, this seems almost certainly true (and I think is even necessary if you want
to satisfy the VNM axioms, otherwise you violate the continuity axiom).

Also, it's well possible that your utility function doesn't evaluate to +10000 for any value of its argument, i.e. it's bounded above.

Since utility functions are only unique up to affine transformation, I don't know what to make of this comment. Do you have some sort of canonical representation in mind or something?