Mr Acty person, you make a valid reason for denying the JW response summarised by SBF, that is; it is a selective list made to serve as a touchstone which appears to serve their own practices. The JW org is only interested in promoting its own selective point of view, it is never objective...after all that is what cults do.
However when attempting to get to the bottom of a problem (the legitimacy of the GB's authority) it is necessary to broaden out their claim to test the validity of their foundation material.
For this they are claiming to be the exclusive preachers of the invisible kingdom of God established in the heavens back in 1914. The fact is that there is no good reason to believe this. The scriptures in Daniel on which the date is based is a fraud (like much of the Bible), the date is calculated on wrong assumptions, Jesus said the kingdom would come in his day. The whole mixture of asumption, probability and lies is as nutty as a fruit-cake.
In other words anyone can make out that they are the chosen one to tell the world by using their own selection of words from the Bible.
Was a violin made to play only one tune?
So I'm suggesting that the authority for the WTBTS gb is invalid because:
A they have failed in their imagined divine mandate and reason for their existence: to proclaim Armageddon for the generation of 1914
B that the Bible on which they base their claims is being exposed as a dying superstition.