answer: you are correct - "to worship" isn't the original.
13 I saw in the night visions, and, behold, there came with the clouds of heaven one like unto a son of man, and he came even to the Ancient of days, and he was brought near before Him.
?? ??? ??? ????, ???? ?????, ??? ????? ???? ??????, ?? ??????; ????? ???? ???, ??-?? ????, ???????, ??-?? ?????. {?} 14 And there was given him dominion, and glory, and a kingdom, that all the peoples, nations, and languages should serve him; his dominion is an everlasting dominion, which shall not pass away, and his kingdom that which shall not be destroyed.
None of Daniel is prophecy about the Jewish Messiah. Daniel is referring to upcoming rulers (starring for my more knowledgeable contacts to give details).
as for the septuagint:
The Septuagint
This was the Greek version of the Hebrew Tanakh.
Jews DID NOT translate the entire Tanakh into the Greek. In fact, they did only the Torah part - the five books of Moses.
The rest was translated by non Jews, which probably explains some of the sheer ERRORS that totally CHANGE the entire meaning of the original language.
The Septuagint was then later revised further by the Church - it's not a Jewish text in any way today and no Jews read it or use it. It's an established CHRISTIAN text.
For more on the Septuagint: go to the Q&A forum here:
http://www.outreachjudaism.org/