For the record, I'm okay if the Teacher of Righteousness is unknown. I don't think the sky will fall.
I think he could be James for the reasons I've been putting forward (and more that I haven't had time to mention yet).
The Teacher is called a priest, and I take into consideration the esoteric meaning of this word (and of the expression "sons of Zaddok") in CD (col. 3 and 4):
"God ordained for them by the hand of the Prophet Ezekiel, saying, 'The Priests, the Levites, and the sons of Zadok who kept the charge of my sanctuary when the children of Israel strayed from me, they shall offer me fat and blood [Ezk 44:15].'
The Priests are the converts of Israel who departed from the land of Judah, and (the Levites are) those who joined them. The sons of Zadok are the elect of Israel, the men called by name who shall stand at the end of days."
I'm at work right now so I have to use an online Vermes and he does not translate this accurately. The scribe has added a vav ("and") to the underlying Ezk. 44:15 (in addition to the one between "the Levites, the sons of Zadok" that Vermes does translate). Also, Vermes adds "(the Levites are)" in parenthesis in the second paragraph to try to explain what is actually a word play in the Hebrew on the first reference to the Levites, "nilvim," and this is a word used in the OT to refer to foreigners:
http://biblehub.com/hebrew/hannilvim_3867.htm
So the scribe has added vavs to the underlying biblical verse to accomodate their esoteric understanding that it means three things ("the priests and the Levites and the sons of Zadok") instead of the original one thing ("the priests, the Levites, the sons of Zadok").
And "the priests" are "the converts of Israel who departed from the land of Judah," not literal priests, and "the sons of Zadok" are
"the Elect of Israel, men called by name," not literal sons of Zadok, and "the Levites" are nilvim, or foreigners who joined them.
You know in spite of all you gained, you still have to stand out in the pouring rain.