1)
What were "Ma'alaleihem"?
1.
Radak: They clung to Ba'al Pe'or, were Mezaneh with the women and served idolatry.
2.
Malbim: They were Mezaneh with Bnos Mo'av; this caused everything. Therefore, when Pinchas did judgment against Zimri, the plague stopped.
2)
Why does it say "va'Tifrotz"?
1.
Radak: It was a great plague.
