This comment and point 5 in your OP are your weakest points and don't logically follow. Archaism in itself does not makes something useless, obsolete or less effective than a modern dialect, especially when a mindful effort is taken to understand the archaisms. It can even open up your mind to a different way of thinking.
You could suppose that a modern translation could be better than KJV, but that preference is going to be subjective and has no business being spoken of as a purported objective or universal fact.
Wow! Now the above was a clear, straight-forward post that really says all that needs to be said about this thread.
In the original post #1 points 1,2,3,4,6 are well-written, true and straight-forward.
But then post # 5 is mostly merely opinion:
It states "The truth is modern versions are much better than the KJV." (Opinion!) Then it says, "The KJV is not a readable version compared to many modern versions because of its archaisms and obscure literal renderings." (Opinion) Then it says: "The KJV was based on late and inferior Greek texts while the modern versions are based upon much older and much more reliable Greek texts." (Opinion!)
An approach that on the basis of mere opinion tries to say that the KJV is not a viable and valuable translation for today is just as bad as the KJV "only" approach that says all modern translations are of the devil.