1)
Why did he wait for them to finish offering the Olah?
1.
Malbim: Through this, they were Chayav Misah for serving idolatry.
2)
Where did the Ratzim and Shalishim strike Ovdei ha'Ba'al?
1.
Malbim: They struck them in Beis ha'Ba'al.
3)
What is the meaning of "va'Yashlichu"?
1.
Rashi citing Targum Yonasan: They cast the corpses of Ovdei ha'Ba'al.
2.
Radak: It is a hyperbole showing how eager they were to send the Ratzim and Shalishim to Ir Beis ha'Ba'al to destroy the Matzevos.