if the Argentinians had been really frightened by the RAF's ability to deliver conventional weapons, they would not have invaded
This is a specious arguement. The Argentinians would hardly have considered any of HM Forces abilities. Their consideration was entirely focussed on HMGs likely reactions. In that they were perhaps not far wrong.
HMG was, apparently, quite defeatist in its ability to recover the islands by force of arms. It was 1SL who was quite positive.
Clearly the RAF would have been wholly unable to recover the Falklands as indeed would the Army have been without the sea lift capacity of the RN. The RN would have been hard pressed to recover the FI without the Army.
The RAF provided some support, not least topping up the task force with stores as the TF reach Ascension. The other RAF efforts have been mentioned already.
True much of what the TF needed could have been done without the RAF but the RAF effort, for instance MRR, enabled quicker exploitation of places like South Georgia. It was a combined effort and one that the RAF did not claim for itself as the major component.