You started your arguments earlier with some 'alternative facts' that THAAD and PDV do mid-course interception. Now without acknowledging your earlier error you're ranting about Aegis and GMD (something you just learnt about recently).I am not talking about the approach what I think is right, I am talking about the approach what BMD follows.
Since @sayareakd had already seen PAD in person, so I think he would be able to get in touch with developers and quote anyone here.
Deploying THAAD in SKorea is definitely about BALANCE OF POWER, because that way US would have the very possibility of intercepting any ICBM originating from China or Russia in its initial stage itself. Try to think about it logically. This is the very reason why US had opted for Aegis with Naval RIM-161 instead of THAAD. That too they would have to deploy it in Black sea for a effective deterrence which they are doing. It all about practical use rather then Theory of Balance.
And where from do you think Pakistan would launch there missiles in India? From Afghanistan? Even if they launch it from Gwadar, its mere 800 km from Gujrat. Now you would not deploy your BMD shield in Delhi to protect it. You would deploy it in a series, from border towards Delhi. So any SRBM or IRBM launched from Gwadar would immediately come in range of any long distance SAM like S400 even before it reaches its Apogee of 80 to 90 km.
AEGIS and GMD are expensive because of the use of next gen computation. But these are much more practical and effective then the THAAD system of 90s. This is the reason why countries like US and Japan are investing more on these systems and long range missile and integrated THAAD with Aegis system.
In your world view an S-400 missile with a maximum range of 400 kms will travel (the mere) 800 kms from Gujrat to Gwadar at a lightening speed before a ballistic missile will reach even 80 kms altitude!!!!!
You had already given me a peek at your 'alternative physics' earlier with equations with Force = mass*distanceTraveled!! I am not surprised that in you mind all of the above nonsense makes sense!!!!
Could you do everyone here a favor? Perhaps you could email few of your friends your thoughts, get feedback and then post it here for the world to see??