What is the meaning of "Rome"?
Rashi: It is casting, like "Ramah va'Yam" (Shemos 15:1). Radak - he shoots arrows via a bow.
Is there only one horseman and one archer?!
Radak: The singular applies to many, as a Klal, like "va'Yhi Li Shor v'Chamor" (Bereishis 32:6).
Malbim: Yes! They were fearful and fled due to one, and due to hearing, without even seeing.
Does the city flee?
Radak: All people of the city will flee. The same applies to "v'Chol ha'Aretz Ba'u Mitzraimah" (Bereishis 41:57) and similar verses. This does not refer to a particular city; all men of every city will flee.
It says "Borachas" only in one other verse - "Mipnei Sarah Gevirti Anochi Borachas" (Bereishis 16:8). What is the significance of this?
Ba'al ha'Turim: Because Sarah caused Yishmael 1 to flee, Yisrael fled from him. "Rome Keshes" is Yishmael, like it says "Rove Kashas" (Bereishis 21:20).
Presumably, this should say the mother of Yishmael. Later, Sarah told Avraham to expel Hagar and Yishmael (21:10), but that was not fleeing, and Hashem agreed (21:12)! (PF)
What are "Avim"?
Rashi: They are thick forests, a place of entanglement of thorns, to hide.
Radak: They are places as high as clouds; this is an exaggeration.
Radak based on Targum Yonasan, Malbim: This is like Ovi; they are forests thick with trees, to hide among them.
What are "Kepim"?
Rashi: The Targum of Sela (rock) is Kipiya. Malbim - they are high rocks.
Why does it say "Bahen" (plural)?
Radak: The verse discusses every city.
It already said that the entire city fled. Why does it add "Kol ha'Ir Azuvah"?
Malbim: They did not flee temporarily; they totally abandoned the city.