I think there is a good explanation for Heb 1.10 that actually enhances the case the for the divine name in the NT and the distinction between Jehovah and Jesus, or YHWH and kyrios in the original.
Because, as you mention, it is the Greek version, not the Hebrew that is quoted here. The Hebrew doesn’t have Lord in verse 26, but the Greek version does. An English translation of the entire Psalm can be read here:
https://ebible.org/eng-Brenton/PSA101.htm#FN2
The question is what did the Greek of this Psalm say before the divine name was removed? The Greek version of this Psalm can be read as a Messianic Psalm, and the Lord in verse 26 is the Lord Messiah rather than YHWH. This is indicated in verse 24 where is says “he answered him”. Who answered who? This is apparently YHWH and Jesus speaking to each other.
This is similar to Psalm 110 where David says, “Jehovah said to my Lord, sit at my right hand” and quoted so many times in the New Testament, applying the “Lord” to Jesus as distinct from YHWH in the same verse.
This raises a question I never see Trinitarians answer. How can they say Jesus and Jehovah are elided in the New Testament when the most popular OT quotation in the entire NT makes the clear distinction between YHWH and the messianic Lord.
The entire point of quoting Psalm 110.1 throughout the NT is to distinguish YHWH from Jesus. Although it’s more difficult to see, because there’s a difference between the Hebrew and Greek versions in Psalm 101/2, the same thing is going on there as the messianic “Lord” is distinguished from YHWH in the original Greek version.
So the NWT probably got it right, the Greek version of the Psalm probably did have “Lord” rather than YHWH in this particular quotation.
As for 1 Peter 2.3 I think they could have used Jehovah there because it could as easily be a reference to Jehovah God rather than Jesus.
Rom 10.13 applies to God because he is the one who resurrected Jesus in the previous verses.
The Gospel scriptures applying Isaiah to the coming of Jesus makes sense because Jesus comes in the name of Jehovah as his representative.