1)
What are "v'Chol Asher Iti"?
1.
Rashi: It is the 100 men in his division.
2)
Why did they blow all around the camp?
1.
Malbim: It was so Midyan will think that there are many troops. Normally, one blows in each troop.
3)
What is the meaning of "la'Shem ul'Gid'on"?
1.
Rashi citing Targum Yonasan: The sword that kills is from Hashem, and the victory is via Gid'on.
2.
Malbim: There is something miraculous attributed to Hashem, and something natural attributed to Gid'on.