First, the civilians should have got out of the way. There was no need for Doval to get brownie points by taking unilateral action (deciding which team to deploy and picking the NSG); there was no need for him to be there at all. Can you imagine Kissinger for instance, sitting in a Vietnamese base waiting for a raid into Cambodia to be completed? There is some deep insecurity in the man that drives him to take prominent positions (out of harm's way) whenever there is a photo opportunity.
Second, there is no reason to believe that the Army would have mobilised large numbers; nobody said so, nobody did so. This was not the Republic Day parade, after all. Pushing masses of people into a situation and hoping that numbers will overwhelm the hostiles is a typically civilian manoeuvre, one that a policeman used to bundobust duty would automatically take. On the other hand, it was the Army, when left to do it right by its own seniors and by New Delhi, that got it right in Black Thunder; a look at the numbers there will be instructive.
Third, you are completely right in suggesting that keeping a low profile and enticing the hostiles to make their move was the correct thing to do. But that did not preclude precautionary measures: guarding the military assets, cautioning the family members and throwing a discreet ring around them (not necessarily of uniformed personnel), giving the hostiles clearly demarcated room to manoeuvre by placing defensive pickets in locations that automatically encourage the hostiles to go where they are wanted to go.
You are right here. The worrying thing about the point of entry is that it should never have been achievable to enter in the first place. That is not an NSG or an SF problem; that is purely a base administration problem. While there is no harm in letting re-employed reservists take up watch-and-ward duties, there needed to have been periodic inspections of intrusion-reporting electronic equipment and of the vulnerability of the perimeter defences. There was also need for the Garudas to be involved as a reaction team located on the airbase itself at all times. What else should an air force special force be doing? That the hostiles got through tells its own tale.
By the time the battle broke out, it was too late for anything but sharpening the pencils for the post-mortem.
Again I repeat: the NSG were not trained for this kind of role, and they were out of place. The overwhelming impression is that they were involved solely because they were under the direct control of the civilian authorities.
There were very many variations possible. Not even one was tried.
An army column is 50 men, hardly a number that would arouse suspicion. The two special forces teams would have barely numbered 10 men each. That's no more than 120 or 130 men in total. The NSG were 130 followed by 80 more. And 30 Garuds were already present. And once the operation started, the army numbers swelled.
I think you are looking for problems where problems didn't exist.
The problem was the vegetation was working for the enemy. So the attackers were well prepared while both the army and NSG were completely unfamiliar with the terrain. I have no military expertise in CI operations, but I see this as a problem for the Garuds and the base DSC who failed to anticipate all the possible hiding spots within the vegetation.