None of what you written is science fiction. By placing SAM's under hardened shelters you are literally giving the enemy enough reason to believe there is something of high value you are hiding there. SAM's are meant to be mobile, they are not meant to stay in the same place. Some big SAM's like the ones which can intercept ballistic missiles are usually kept underground in dense green cover setting. These things are expensive to maintain, pain in the ass actually.
Think about our SSBNs, it carries nukes and it is always hidden lurking under water. Since it's role is defensive it needs to be extra careful where it is going. During conflict it needs to be ready to fire nuclear tipped ballistic missile if the enemy takes out our nuclear missiles and installations. All in all it is stressful to maintain missiles hidden whether it is in submarines sailing underwater or underground. The stressful part here is not so much about financial, it is mainly about command and control. This is the reason US, Russia, France, China build aircrafts to carry nukes. They don't want to be reliant on some under bunker to do the job.
You have skirted the main question.
Can AWACS be used to guide ground launched SAM missiles.
What are the technical challenges to realize that capability. Will the acquisition of this capability offer some advantage.
There are different types of radars ranging from battlefield surveillance radars to massive Over the Horizon radars.
Not all radars are mobile or have to be mobile.
I talked about the enemy destroying Radars installations not taking out SAM'S in isolation.
There are Low Power Radars, Medium Power Radars and High Power Radars etc.
Their search and track range differs.Ranges can vary from a few kilometers to hundreds of kilometers. Not even talking about OTH radars here.
The enemy usually uses Anti Radiation Missiles to take out Medium and High Power Radars.
Would Pakistan not like to take out the Barak 8 or S400 radars thus rendering the Barak 8 missiles inoperative.
Suppose assume that after the main radar is destroyed our airborne AWACS can still guide Barak 8 missiles to counter Pakistani fighters and Air to Surface missiles like the Raad or Babur.
Normally we would have to wait for an replacement radar to make the Barak 8 system work again.
What about the MRSAM systems used to guard IAF Air Bases. The Air Base is a static installation.Do they need highly mobile SAM systems. Assume that the main radar of the Barak 8 system is destroyed. What happens now.
And even mobile radars can be targeted. The anti radiation missiles will follow the direction of the signals.You have to switch off the radar to disrupt the missile seeker. Or use decoys to mislead the seeker.
My question - should we even try to enable our AWACS to guide ground launched SAM's.
In a worst case scenario where the enemy manages to knock out our main radars.
And remember SAM'S are not ICBM's .Why do you need a gigantic launch complex to store and launch SAM'S. I have already said that the launch pads will be quite small and concealed/camouflaged.