Actually they show up in Pliny the Elder and Philo wrote about them. I think the best fit for Qumran and the scrolls is that it was an Essene settlement and that the scrolls were their documents. The Damascus document in particuliar points in that general direction. But that is all we have, general directions. To point to textiles as proof is non-sensical in my opinion. The absence of wool in the caves means nothing more than no wool was found which could mean the scrolls were hidden in summer when wool was generally not worn by the rich.
Now the question of who were the Essenes I think is more interesting. Were they a break away sect from the Sadduccees as some claim? I don't think so because more than just the Torah is found among the Dead Sea Scrolls. The Sadduccees really only submitted to the Torah. Were the Essenes a break away from the Pharisees? This may be more tenable. During the Hasmonean period, the Pharisees developed from a group generally labeled the Hasidim. Some see a common thread in the sects (Pharisees and Essenes) in their practice of Halakhah which the Sadduccess really did not practice. The difference in their practice may be the real difference between Pharisees and Essenes. Again, nobody knows this, it is just conjecture.