1. In Parashas Vayigash it says "U'bnei Dan Chushim."
2. The question is, why use the plural "bnei" for a single person?
3. The Ibn Ezra suggests that there was another brother who died.
4. The Ba'al HaTurim says that Chushim can mean both "haste" and "a thicket of reeds."
5. R' Shlomo Fisher notes the reflexive responsibility of Chushim, or Chalutzim, and "Me'asef l'kol ha'Machanos."
6. Targum Yonasan translates Chushim as "speedy" and as "craftsmen."
7. The Gra added words to the nusach of the Al HaNisim for Chanukah so it added up to 54 - the number of times the name Haman appears in the Megillah, and the number of letters in the 10 sons of Haman - and the number of Dan.
8. The tikkun of Dan on Purim is fairly obvious - they were the ones expelled by the Ananei HaKavod who were killed by Amalek in the Midbar.
9. The Al HaNisim for Chanukah has 92 words - that also corresponds to Dan as the ninety-second pasuk in the Torah "Na va'Nad [Nad=54=Dan] tihyeh ba'aretz."
10. The pasuk corresponds both to "Galus" Dan (in Sefer Shoftim, from the middle of the land to its north) and to Galus Yavan. These were both internal exiles - they took place "ba'aretz."
11. The craftsmen for both the Mishkan (Betzalel and Ahaliav) and the Beis HaMikdash (Shlomo and Chiram) were from Shevet Yehudah and Shevet Dan respectively.
12. These two shevatim waged war against Midyan.
13. Moshiach is from Shevet Yehuda on one side and from Shevet Dan on the other side.
14. The Midrash states that Chushim came to assist Yehuda when he shouted at Yosef.
15. Chushim killed Esav (see Tosafos, Gittin 55b, that it was through both Yehuda and Dan!).
16. Yehuda leads, Dan collects the stragglers - Meleches Shomayim unites them and "na'utz sofan b'techilasan."
17. Dan was the "Nechshalim Acharecha" because they were the "Me'asef l'Kol HaMachanos" - in that they were like a thicket of reeds, a barrier against others falling out. This is also the middah of "Din" - which separates parties that are in a dispute, and "Mishpat" - a line that is not to be crossed.
18. They had this role in EY too. Yarden=Yarad Dan - the Jordan flowed down from the second nachala of Dan, and it was the dividing line between EY and Chu"l (Reb Tzadok) - "Lev Ragaz" is only before one crosses the Jordan (Gemara Nedarim).
19. Their nachala in the North centered around Layish (a young lion) or Leshem - the Izhbitzer in Parashas Tetzaveh sats that indicated that Dan possesses "Tekifus Gadol l'Shem Shomayim."
20. Shimon (Shemi'a) heard well (Reb Tzadok says that RSBY was from Shevet Dan); Chushim was hard of hearing - Dan's position on the border makes that beneficial, to prevent mesitim u'medichim whispering in your ear
21. Dan has a correspondence to Rome, to Caesaria (Reb Tzadok, Dover Tzedek 97b).
22. "V'gam es ha'goy asher ya'avodu dan Anochi."
Yishma Chacham v'Yosif Lekach