The NWT puts Jehovah in all the places where the writers of the NT quote from the OT.
Not necessarily: e.g. 1 Peter 2:3 NWT, " provided YOU have tasted that the Lord is kind," while the cross-reference sends back to Psalm 34:8 NWT, " Taste and see that Jehovah is good".
There are a few places where thet should have lest it out.
Indeed, especially when the insertion of "Jehovah" destroys an argument explicitly applying the use of "Lord" in the Septuagint quote to Jesus: please read Romans 10:9-15; 14:7-9; John 12:48-51 in any other Bible and then compare the NWT to see what is left of it.
While on earth Jesus was promoting his fathers will and he was not afraid of controversy so he would have used his fathers name.
How do you know (or think you know)? Because controversies about such things as Sabbath observation, ritual washings, fastings are recorded in the Gospels. On the contrary there is no NT mention of any controversy regarding the use of the name Yhwh, which would have been a much more important issue.
No original copies of the writings of the NT exist. Because of the tradition of the Jews not to use Gods name and because the Paul to the Theselonians said that a falling away would come (2:3 ?Let no one deceive you in any way; for that day will not come, unless the rebellion comes first, and the man of lawlessness is revealed, the son of perdition,?) The word for ?falling away? according to Strongs is apostasia apostasia ap-os-tas-ee?-ah; feminine of the same as 647; defection from truth (properly, the state) ["apostasy"]:?falling away, forsake. There is no proof but it would seem as if those the copied the originals left out the name of God due to the tradition of not using it.
This reasoning implies that the NT text has
not been transmitted correctly: so how can we trust it for anything? How come, for instance, that JWs are able to argue from NT texts in "apostate manuscripts"
against the "apostate Trinity doctrine" if the text has been modified to suit the "apostasy"? You can't have it both ways.