...So a chancy, dangerous attack on the mainland is simply not necessary. Moreover, the RN is now busy covering the landings; to carry out an attack would mean stopping that, getting closer to Argentina (which would help what's left of Arg air force to get to them, as well as any survicing sub (?) ) and launch a massed raid with the small pool of planes it has. The chances of doing that with no losses are very slim. I'd like someone to run numbers, but I'm pretty sure a Vulcan raid would involve even more air refueling to happen, with all the possibilities for problems that means...
And imagine this (admitedly unlikely) scenario: while the RN sails on to carry out the attack, at the same time the Arg AF is launching their massed strike on the landing areas. Where most of the air cover and ship SAMs are gone...
What leads you to believe this is a 'chancy, dangerous' option? There is no need to, nor rhyme or reason in 'getting closer to Argentina'. Perhaps you could tell me exactly where you think Eagle is likely to be when launching a strike package which out-ranges any opposition she might conceivably face (clue: it's not going to be off the coast of Comodoro, at anchor...). Bear in mind too, that even with her air group 'occupied', the task force still has 'Vince & Hermes with, presumably, a similar number of Harriers at their disposal as per OTL. There is, in other words, no need to 'stop' or postpone the landings.
An attack of this nature may be launched by the RN at a time of their choosing - they have full all - weather capabilities, and Argentina doesn't. If the FAA are going to launch against the landings, the attack will come at dawn or sometime shortly thereafter. Any such attack will proceed via a limited choice of approach corridors - there will not be sufficient fuel to allow wiggle room here, which all makes prediction and / or interception of such an action rather straightforward - particularly with the aid of AEW assets. I said early on that I believe a 'four + four' package would be more than sufficient for airfield attack - that doesn't impede the standing CAP at all.
Any combat operation carries risk, but I rather fancy that the odds of 'doing that with no losses' are pretty good, actually. Argentine airfield defences at the time (and now, for that matter) were, frankly, a bit shit. And anything either already in the air, or launched to greet the raid gets a very warm 'hello' from Mr. Skyflash from forty to fifty odd miles out. Even if there are losses, it's much preferable - by ANY standards - to lose an aircraft with two crew, rather than a ship with hundreds. Indeed, it's the whole raison d'etre behind attacking the airfield in the first place...