I know for an absolute and incontrovertible fact that it is impossible to translate the Hebrew, Aramaic and Greek manuscripts into English without substantially adding to and taking away from the original because of the differences in the Languages.
This, of course, is irrelevant. The Old Testament Texts primarily used by the translators of the King James Version were the Complutensian Polyglot (1517) and the Antwerp Polyglot (1572). Today we have Masoretic manuscripts dating from the 10th century. For portions of the Old Testament we now have manuscripts from the second century B.C. Approximately 800 Hebrew manuscripts of the Old Testament have now been studied. The King James Translators had only one text for the Septuagint, we now have many. They had only a corrupted text of the Latin, we now have Codex Amiatinus (A.D. 541) representing Jerome's final edition. Thus the textual foundation of the King James Old Testament is very poor.
The New Testament text primarily used by the translators of the King James Version was the third edition of Robert Estienne’s text of 1550. It is commonly called the Textus Receptus although the true Textus Receptus was not published until 1633. Only one of the five primary uncial manuscripts of the New Testament, the Codex Bezae, was yet available and apparently it was not used. Of the 5,359 early Greek manuscripts we now have of the New Testament, the King James Version translators had less than 25 available to them and they were of comparatively late origin. Indeed, their primary text was so poor by today's standards that it is commonly called a "corrupt" text by today's scholars. It contains words and phrases that are not found in any known Greek manuscript. For example, the phrase translated, "him that livith for ever and ever" (Rev. 5:14) and the words translated, "and he trembling and astonished said, Lord, what wilt thou have me to do? And the Lord said unto him" (Acts 9:6).
It also contains many other words and phrases that are not found in the best manuscripts and are either known to be glosses written by the scribes copying the manuscripts or are of very questionable origin. These include 16 whole verses: Matt. 17:21; 18:11; 23:14; Mark 7:16; 9:44; 9:46; 11:26; 15:28; Luke 17:36; 23:17, John 5:4; Acts 8:37; 15:34; 24:7; 28:29; and Romans 16:24. Also included are the following words and phrases:
"For thine is the kingdom, and the power, and the glory, forever. Amen." (Matt. 6:13)
"I trow not" (Luke 17:9)
"not" (Rom. 4:19: Col. 2:18)
"who walk not after the flesh, but after the Spirit." (Rom. 8:1)
"thou shalt not bear false witness" (Rom. 13:9)
"if" (2 Cor. 5:14)
"of our Lord Jesus Christ" (Eph. 3:14)
"through his blood" (Colossians 1:14)
"and were persuaded of them" (Heb. 11:13)
"him" (1 John 4:19)
Many other examples could be cited here.
In addition, the text of the King James Version omitted a number of words and phrases that are included in the best manuscripts:
"nor the son" (Matt. 24:36)
"and came to him" (John 19:3)
"by the Holy Spirit" (Acts 4:25)
"of Jesus" (Acts 16:7)
"God" (Rom. 8:28)
"just as you actually do walk" (1 Thes. 4:1)
"unto (or "in respect to") salvation" (1 Pet. 2:2)
"according to the will of God" (1 Pet. 5:2)
"and such we are" (1 John 3:1)