This is a very fair and careful analysis of the various translations.... I was almost expecting a "KJV only" argument, but was pleasantly surprised.
Personally I use the English Standard Version (ESV) for study (a very recent and accurate translation). The New King James Version (NKJV) is also about the most beautiful of the modern tranlations, preserving (relieving one of my pet peeves) the tradition of capitalizing the pronouns for God, as He's definitely worth it!
Lord willing I'll start learning Koine Greek this summer....
I was liking it too, but have found occasional problems. For instance, in I Tim 3, the word 'episkopos' is translated 'overseer', which is a generally reasonable translation for the wider use of that word at the time I Tim was written. However, this being true, then one would expect consistency when the word 'diokonos' occurs a few verses later. That is to say, one would expect the translation to say 'servant'. But no, the word given is 'deacon'.
That said, the number of occurrences so far is small of this kind. It's a very good translation, overall.
I've been a NASB man myself for 20+ years, but recently started reading from the NKJV and enjoying it. I hear good things about the ESV, but as it took me 2 decades to try something new, I doubt I'll be making another change any time soon :P