1)
What is "Be'alunu"?
1.
Rashi: They became masters over us, and pressed us for payment.
2.
Radak: They treated us like their monetary acquisition, and wanted to force us to deny Emunah in You and Your unity
2)
What is the significance of mentioning His name?
1.
Rashi: We will mention His name of Elokus, to say that only our G-d is G-d.
2.
Radak: Even though the nations were cruel masters over us, we mention only Your name. If we would mention other gods, like our enemies that were over us, We would have been saved from them, and in grandeur like them. We did not want this; we suffered affliction and mentioned Your name to them, and said that we trust in You, and we will not switch You for another.