1)
Why does it say "v'Chi Azavnu" with the prefix Vov?
1.
Metzudas David: It joins with the Vov in "va'Na'avod" - we abandoned Hashem and served the Ba'alim.
2.
Malbim: This is said in astonishment. Indeed, we sinned - but did we abandon Hashem?! We served the Ba'al to be an intermediary between us and Hashem! 1
1
This is difficult. They did not serve Him at all (refer to 10:6:1:1)! Also, do they think that their intent should exempt them from punishment? Also the Egel was meant to be an intermediary between Yisrael and Hashem, and Hashem would have killed all of Yisrael for it, if not for Moshe's Tefilah! (PF)
