Matthew 15 opens with an argument between Jesus and the Pharisees over religious traditions. It's important to realize (although easy to miss) that the hand washing that is talked about here is not simply for cleanliness, but rather they're talking about a kind of ritual hand washing; I'm afraid I forget the full details at the moment. Jesus is making a statement about how the commandments of God are of higher value than mere traditions, and uses a couple of passages about a child's relation to their parents. Yeah, the law about putting a disobedient child to death is pretty severe, and I honestly don't feel equal to discussing it at length, but for the purpose of this passage, I think the point that Jesus is trying to make is that honoring your parents is serious business according to God, and the Pharisees had made a tradition that allowed people to not care for their parents. Whatever you may feel about the laws Jesus brings up, the thing is that people were using excuses to not follow them, and placing tradition over the law of God. What Jesus says in verse 13 may sound rather harsh as the SAB takes it, but I think in this context it can be taken as saying that tradition, in the end, is pointless unless it conforms to the will of God.
As I've said before, history is not one of my strong points, so I'm not sure what to say about Ezekiel's prophecy about Tyre. I'm sure there are others who have examined this topic, so maybe if I remember this later and feel ambitious, I'll look into it.
The story of the Canaanite woman in verses 21-28 is an odd one, as it makes Jesus look pretty uncaring. The interpretation that I've always heard of this story is that Jesus was testing the woman to give her a chance to show her faith. Admittedly it's still strange, but if Jesus knew that she would be that persistent, it could serve as a good example of faith and humility to other people.
Again this chapter ends with a miraculous feeding. As with the last one, there is a huge amount of leftover food, and once again, the amount is perhaps symbolic, as this would seem to be a mixed crowd (not just Jews) and seven is considered to be a number of completion. The SAB suggests that these two stories may be "the result of two oral traditions of the same fictitious story." While that doesn't seem too unreasonable, it should be noted that in the next chapter, Jesus refers back to these as two separate stories.