Bear in mind that translation involves a lot of interpretation. In the case of Heb 1:6 and lots of other places where the Greek word "proskuneo" is used, the translator needs to make a judgement ab where to select from a whole range of meaning. "Proskuneo" can signify anything from simply paying respect (as to a civil dignitary) to worship. So it is never straightforward. For example, in the case of the wise men/magi/astrologers visiting the infant Jesus the word, in my opinion, should be rendered something like, "paid respect."
For the Kyrios/Jehovah question in the NWT Greek Scriptures, you might find this free download useful: www.smashwords.com/books/view/170997 It deals with the relevant principles of translation and gives an analysis of every instance of Jehovah in NWT Greek.