Your interpretation of Jehoiakim’s 3rd and 4th years is (still) incorrect and indicates some ignorance of the different dating systems used (but is closer than the Watch Tower Society’s interpretation). The rhetorical suggestion that ‘Maybe Nebuchadnezzar was crowned in April” in particular indicates some ignorance of the actual history of the period. Daniel doesn’t count accession years as part of the reign and uses Nisan-based years. 2 Kings uses Tishri-based years for Judah, Nisan-based years for Babylon, and counts accession years as the first regnal year. (This is why you’re generating some additional invented confusion regarding 624 and 625, setting aside their displacement by 20 years.)
The JW interpretation of Daniel 2:1 deliberately uses the word “kingship” instead of “reign” to try to imply that it means ‘vassalage’ though this has no basis in the original text. They do not claim Daniel was taken to Babylon the year before that. (They place the interpretation of the dream several years after Daniel’s training, ignoring the fact that Daniel and his friends were supposedly known as the wisest in the land after their training but then Nebuchadnezzar has never even heard of Daniel when he wants his dream interpreted. In the story, Daniel actually interprets the dream during the training period.) It is good that you point out their mangling of the period. But it isn’t an outstanding revelation that Nebuchadnezzar’s 19th year is the same year according to the made up JW method of counting ‘kingship’ from 607.
Your mispronunciation of ‘vassalage’ is a little distracting. The ‘-age’ in’ vassalage’ is properly pronounced the same way as in ‘marriage’.