A lot of this chapter is repeated from earlier portions of the Pentateuch. In particular, the warning against intermarriage was first stated in Ex 34:11-17, and it included similar language about: clearing away a list of nations, make no covenant with them, do not intermarry (taking daughters for your sons, giving daughters to their sons), and destroying their religious symbols; the altars, sacred stones, Asherah poles and graven images. This demand that the Israelites separate themselves from the other nations of the promised land is what I call the "principle of separation" in the Pentateuch, which I first mentioned all the way back in Ex 20, when discussing the first commandment, appropriately enough (I discussed it a few times after that, in Ex 32, Lev 11, Lev 18 and Lev 21).
This chapter commands the Israelites to maintain a social and cultural separation from the other nations, refusing to intermarry or relate to the other peoples. This is related to the first commandment because the social separation is intended to reinforce and support the religious separation demanded by the first commandment. The command to destroy the sacred stones and Asherah poles is similarly intended to protect the Israelites from worshiping these things.
Verses 9-11 are interesting because they are a modified and expanded form of Deut 5:9-10, which was stated as part of the second commandment. From this, we can infer that the command to destroy the altars and graven images in v. 5 is a specific stipulation corresponding to the second commandment (you shall not make an idol). It's a little hard to tell the difference between the first and second commandments because idols are nearly always associated with other gods, but in this case vv. 9-11 gives us a hint that the author has moved on from the first to the second. That said, the author is unlikely to be "done" with the first commandment, so it is likely that later sections will continue to correspond with the first commandment.
The rest of the chapter is an encouragement of the LORD's blessings if they keep the covenant and a pep talk in case the Israelites get afraid of invading the promised land, which is a very common theme. The blessings are reminiscent of Lev 26:3-13. Lev 26 also includes a provision about "not making" idols, images or sacred stones, which is similar to v. 5 in this chapter.
The pep talk is a reminder that the LORD is with you, the LORD will destroy your foes, the LORD your God is in your midst and is a great and awesome God, etc., etc. This section is very similar to Ex 23:20-33. This section of Exodus, which is part of the covenantal law that Moses shares from Ex 20-23, uses many of the same expressions as Deut 7 as a whole. It includes a list of nations that the Israelites will destroy, a command to not worship their gods, a command to destroy their sacred stones, a promise of material blessing for the Israelites with emphasis on fertility and removing sickness, blessed bread and water, a terror and confusion sent upon their foes, a statement that the LORD would destroy them "little by little", and a renewed demand that the Israelites make no covenant with the inhabitants of Canaan or else the Israelites risk being ensnared.
One of the key words tying these two chapters together is "tsiraw", which is Hebrew for hornet or wasp. I had mentioned this briefly in my commentary on Ex 23. Tsiraw is a word used only three times in the OT; first in Ex 23:28, second in Deut 7:20, and third in Joshua 24:12 (which discusses the same topic, the LORD sending "the hornet" against Israel's foes). So this word is only ever used in reference to this "hornet" which the LORD sent against the Canaanite nations as a preface to their larger military invasion. That's why the translation is so strange, because modern translators don't really have anything else they can cross-reference it with.
As with Ex 23:28, it clearly refers to some sort of malevolent force sent to harm their enemies in anticipation (or collaboration) with the Israelite invaders. The exact nature of the force is indiscernible, but since the word only occurs here and there we can tell that this chapter of Deuteronomy is meant to be largely equivalent to Ex 23.
With all that said, I think the rest of the text is largely self-explanatory given what I have already written about Deuteronomy, so at this point I will move on to chapter 8.