I'm no scholar on Textual Criticism, nor do I care about the arguments on the WH, or the TR versus the NA28. I examine the arguments made by the scholars on various readings. For example, I have Bruce M. Metzger's A Textual Commentary on the Greek New Testament, 2nd Ed. 1994. I can read his argument on 2 Thess. 2:13 supporting the translation "firstfruits", and I then can compare with the argument made in the Net2.1 Bible which reads:
Critical Text Note:
"tc ‡ Several MSS (B F G P 0278 33 81 323 1505 1739 1881 al bo) read ἀπαρχήν (aparchēn, “as a firstfruit”; i.e., as the first converts) instead of ἀπ᾿ ἀρχῆς (ap’ archēs, “from the beginning,” found in א D K L Ψ 1175 1241 M it sa), but this seems more likely to be a change by scribes who thought of the early churches in general in this way. But Paul would not be likely to call the Thessalonians “the firstfruits” among his converts. Further, ἀπαρχή (aparchē, “firstfruit”) is a well-worn term in Paul’s letters (Rom 8:23; 11:16; 16:5; 1 Cor 15:20, 23; 16:15), while ἀπ᾿ ἀρχῆς occurs nowhere else in Paul. Scribes might be expected to change the text to the more familiar term. Nevertheless, a decision is difficult (see arguments for ἀπαρχήν in TCGNT 568), and ἀπ᾿ ἀρχῆς must be preferred only slightly."
I also check my Bible software entry on this:
Thessalonians 2:13:
TEXT: "God picked plyou as firstfruits for salvation"
EVIDENCE: B F G P 33 81 1739 1881 some lat vg syr(h) cop(north)
TRANSLATIONS: ASVn RSVn NASVn NIVn NEBn TEV
RANK: C
NOTES: "God picked plyou from the beginning for salvation"
EVIDENCE: S D K L Psi 104 614 630 1241 2495 Byz Lect some lat syr(p) cop(south)
TRANSLATIONS: KJV ASV RSV NASV NIV NEB TEVn
COMMENTS: There is only one letter's difference between "as firstfruits" and "from the beginning." The UBS Textual Committee preferred "firstfruits" because the prepositional phrase "from the beginning" is not used elsewhere by Paul while he uses the word "firstfruits" six other times, and in two of those places some copyists have changed "firstfruits" to "from the beginning."
Every translation is a mix of Formal Equivalence and Dynamic Equivalence. Interpretation must be involved in any translation. On that question, Daniel B. Wallace has a good article online, 15 Myths about Bible translations -
Perhaps the number one myth about Bible translation is that a word-for-word translation is the best kind. Anyone who is conversant in more than one language recognizes that a word-for-word translat…
danielbwallace.com
About Gal. 6:16, looking at the RSV,
"But far be it from me to glory except in the cross of our Lord Jesus Christ, by which the world has been crucified to me, and I to the world. For neither circumcision counts for anything, nor uncircumcision, but a new creation. Peace and mercy be upon all who walk by this rule, upon the Israel of God." (Gal 6:14-16 RSV)
The Net2.1 Text note reads:
"tn The word “and” (καί) can be interpreted in two ways: (1) It could be rendered as “also” which would indicate that two distinct groups are in view, namely “all who will behave in accordance with this rule” and “the Israel of God.” Or (2) it could be rendered “even,” which would indicate that “all who behave in accordance with this rule” are “the Israel of God.” In other words, in this latter view, “even” = “that is.”
Taken in the full context, I believe (2) is the correct meaning and translation. This is the opinion of John Wesley, Matthew Poole, John Gill, Matthew Henry, etc. The Cambridge Bible comment reads as follows, summing up the best argument:
"It seems better, however, to regard the expression as intended to sum up the ‘as many as’ in a phrase which is closely identified with the whole argument of the Epistle, ‘If ye be Christ’s, then are ye Abraham’s seed and heirs according to the promise’. These are ‘the Israel of God’, whether Jews or Gentiles, for ‘the Jew is he who is one inwardly in the spirit, not in the letter’. Rom_2:29. So that the blessing is invoked on all who walk according to the rule enunciated, and so in fact on the true Israel, not Israel after the flesh, but the Israel of the promise and of God."