1)
Why does it say "Al Yadav v'Al Raglav"?
1.
Rashi: It is with all his strength and speed.
2.
Radak: It was hard to go with his legs alone, so he used also his hands. Targum Yonasan says that Botzetz was slippery.
2)
What is the meaning of "Memoses"?
1.
Radak citing Targum Yonasan: [The weapons carrier] was killing. Chomas Anach - he killed with iron, or a staff. Only Yonason had a sword!