Radak citing Targum Yonasan: The 'angel' was a Navi. There, Hashem told him to say this to Yisrael.
2)
What is "ha'Bochim"?
1.
Rashi: It is a place. Radak - it is called so because they cried there (verses 4,5).
3)
To whom did he speak?
1.
Radak: He spoke to all of Yisrael. The Navi gathered them, or they were already gathered.
4)
Why did he mention Yetzi'as Mitzrayim?
1.
Rashi: Hashem took us from Egypt on condition that we dispossess His enemies [from Eretz Kena'an].
2.
Malbim: I took you from the lowest level - slavery in Egypt, to the highest - I brought you to Eretz Kena'an! I said that you should feel obligated to serve Me amidst appreciate of this, and I made a permanent Bris with you [on condition?]
5)
Why did he say "E'eleh"?
1.
Radak: We often find the past in a future conjugation.
