"You can either sub for "Damaging Ice-Move", or "Ice Punch". The former will trigger if a combination contains any Ice-Attack, the latter if "Ice Punch" is used in a combo or not. You cannot sub for "a combo including Ice Punch and being ice typed" as well as "Ice Punch alone" in one substitution - that takes 2 substitutions.
And yes, "Physical Ice-Typed attack" is illegal."