What are the implications of "ve'Eileh Ya'amdu al ha'Kelalah"?
Oznayim la'Torah (citing the Yalkut Shimoni): It implies that, when punishment comes upon the world, the Tzadikim suppress it. 1
Refer to Bamidbar, 23:8:1:1.
See Oznayim la'Torah.
In which order were the B'rachos and K'lalos said?
Yerushalmi Sotah, 7:4: Although the current Pesukim suggest that they first recited the B'rachos and then the K'lalos, the Pasuk in Nitzavim, 30:1 "ha'Berachah ve'ha'Kelalah" (singular) teaches us that they recited them one at a time, first the B'rachah then, the K'lalah.
What is the significance of the tribes that were on Har Eival for the K'lalos?
Riva: It was the sons of the Shefachos, Bilhah and Zilpah, plus Zevulun, the youngest of the sons of Le'ah, and Reuven, who had to answer Amen to "Arur Shochev Im Eishes Aviv" - in Pasuk 20, because he switched his father's bed.
Shulchan Sh'lomoh: They were the first tribes who would ultimately be exiled. 1
Presumably because they were guilty of transgressing the sins listed here. Eichah Rabasi (Pesichah 5) states that the first were Reuven and Gad, or Zevulun and Naftoli, but I did not find anyone who says that Asher and Dan followed them. (PF)