800 NAS were reluctant to carry out many CAS missions because the the Captain and Wings on Hermes thought that low level CAS would be dangerous without someone in a rear seat. This was becuase Hermes' Captian and Wings were from the Buccaneer world. 801 NAS were a little more adventurous but were tied up most of the time providing CAP. The Harrier GR.3's were few in number and as has been mentioned were vunerable to AA fire. Its important to remember that the the Royal Navy intially only had 20 Sea Harriers and 4 Harriers, these were vital to the British campaign and would not be risked to often. One advantage that the British did have was the ability for night strikes which the Argentinean aircraft largely lacked, the exception being the Super Etendard which were thin on the ground. Of course its downright dangerous to fly CAS sorties at night, there's simply to great a risk of hitting your own people because of the small distances involved. It might be risked if there was a good moon though. The British did have an advantage in terms of CAP though, because of the Blue Fox Radar, superior avionics (the computer and Head Up Display really were excellent) and to a certain extent the AIM-9L. The combat pairs employed by the British also worked well and the Sea Harrier had proven an excellent dogfighter. The Argentinean Aircraft's speed advantage was lost when comat needed to be joined because you cannot fight at supersonic speed. The Argentineans were forced to fight in the Sea Harriers element when they wanted to engage the British.
The Royal Navy was fully able to deal with the Argentinean Navy, Argentina's Admirals realised this after they lost Belgrano. British SSN's were controlled from Northwood HQ near London and were assigned kill boxes. Each SSN would track vessels in their kill boxes and transmit a list of what they had spotted to Northwood via satellite, Northwood would then talk with the war cabinet and decide what action should be taken. However there were circumstances in which SSN's could take action against Argentine vessels. When Belgrano was sunk HMS Conqueror had applied for a change to the ROE so Belgrano could be sunk. Woodward had communicated to Northwood that he was worried about the possibility of an Argentinean pincer movement on the British Task Force and so Northwood and Thatcher gave permission for a change in the ROE which resulted in Conqueror sending Belgrano to the bottom. After the loss of Belgrano the Argentineans sensibly withdrew the bulk of their Navy into home waters. Had 25 de Mayo actually ventured out of Argentine waters she would have been vulnerable to attack by SSN's. Once in blue water the Argentines would have been at the mercy of Royal Navy SSN's, do not underestimate the ability of the SSN's at this point in History the Royal navy had put a lot o emphasis on SSN operation because of the perceived Soviet threat. Getting 25 de Mayo out to sea would not have been much of an advantage for the Argentineans as the Falklands were already under the umbrella of land based Argentinean air cover. Sending out the 25 de Mayo would have been needlessly risky. Argentine escorts armed with Exocet were also of limited usefulness because they weren't as flexible weapons platforms as the air launched variant. Surface warships are a lot slower and a lot easier to find and destroy than attack aircraft. The Royal Navy was and is so much more powerful than the Argentinean navy not to say that the Argentinean navy didn't pose a threat because it did. Argentina pursued a sensible strategy in the Falklands they used their large air force as their primary means of attacking the British. This was exactly the right thing to do as it risked fewer Argentinean lives than sortieing Frigates or other surface vessels. The terrain of the Falklands allow aircraft to pop up from no where on the radar screen deliver their ordinance and get out. The Argentine advantage in numbers was huge but the 20 or so Sea Harriers of the Royal Navy were excellent machine with very well trained crews. The shear number of escorts sortied by the British was also difficult for the Argentineans to overcome, the British defensive screen in terms of both warships and aircraft proved highly effective and despite losses the British did not lose their mission critical Aircraft Carriers. In reality the Royal Navy held to many trump cards compared to the Argentinean Navy, SSN's and the Sea Harrier being the most significant in that order. The Argentineans were sensible not to risk further losses against Royal Navy SSN's. ;)