You would follow the rules as written. As you just described, it would make Combat Familiar very powerful by simply giving +2 attack, but still be well within the rules of 6e.
My assertion is that in order for something to be a modifier, if mode first declare what it is modifying. Combat Familiar only says use itself. Thus it can't be a modifier but a profile.
If Combat Familiar read:
"Two additional attacks resolved at S4 AP-" there would be no question. It would define itself as being the last operation. However, it defines itself as a profile, a first or primary operation.
It says 2 additional attacks these would be resolved at the normal S &
AP of the melee weapon if not modified to S4
AP-. I'm not convinced at all that the "resolved at" wording would change how the rule works at all. Maybe I'm not fully understanding your point. Please expand why you think modifying the S &
AP of the attacks would only be modifying them if using the resolved at language.
If it is a profile. What type of profile is it? If a weapon profile why is it missing information? Also if it is a weapon profile how do you resolve pg51 which tells you that you must choose which weapon profile to use. If it is a different type of profile please tellme which ytype it is and where it is defined?