I think this may be covered in more detail elsewhere in the Mosaic Law, but God wants the people to "sanctify" their firstborn sons to God. Here, it's not entirely clear what that entails, and I'm not going to bother to look it up elsewhere, just because I'm feeling lazy. The only thing I care to respond to at this point in time is the issue of sexism in verse 2. There may be a number of reasons for this, including a number of ones that indeed would be considered sexist no matter how I put them. I'd like to suggest a couple that I don't think are quite so sexist.
First of all, it seems to be hinted heavily that much of what is set upon the ancient Israelites as law was given to be in contrast to the pagan nations they intermingled with. In this particular case, I believe that this may be at least in part a response to the killing of baby boys by Pharaoh. The Egyptians kill the baby boys of the Israelites, God kills the baby boys of the Egyptians, and in order to remember that God avenged their blood and saved future generations from genocide, they have to remember to "sanctify" their sons that would have been killed if they had not been saved from their Egyptian captivity.
Another possibility, which is not so far removed from the above, nor entirely free of sexism, is that God is simply following a societal standard. I think many of us find it distasteful at times, but it seems that God was sometimes in the practice of doing things in a manner that was according to the times. If something was outright sinful, He'd demand it stopped. If something was less than ideal, but not *evil*, then he'd allow it to continue at times. A case could be made for polygamy being within that sort of domain. It's not bad enough to outright ban, but not really God's ideal, either, so it's neither banned nor sanctioned. One thing that ought to be noticed, however, is that when the time was right for it, God would sometimes throw in exceptions.
Now this sanctification of firstborn males also seems to apply to livestock, although in this case, there's a very straightforward application given right here: they have to be killed by breaking their neck. The SAB notes this as violent, and I would agree and disagree. The issue of sacrifice aside (which I have addressed many times previously) it occurs to me that if you are going to kill an animal, breaking its neck is probably relatively fast and painless. So while one might find sacrifice in general barbaric perhaps, I'm not sure what would be a better method, other than perhaps beheading the animal, I don't know.
In response to all of this, and as an observation on verse 15, the SAB says, "The Lord killed so you should too". Well, yeah. We're talking about animal sacrifices here, and God saving an entire nation... Maybe it's just a matter of perspective, but I don't see a great problem here.
In verse 17, there is mention made of "the land of the Philistines", which causes some concern. Once again, not being fully aware of the historical backdrop of all of this in full, I can only take the SAB's claims about the Philistines on faith at this point, not knowing where to research this info. Something I can say, though, is that aside from the possibility of an anachronistic label used intentionally as I felt might be the case elsewhere, there is something going on in the language here that is worth noting. The Bible does not say, "that God led them not to the land of the Philistines" says "that God led them not through the way of the land of the Philistines". Wherever the Philistines may have been at this time, it may be that going through that area might have been nominally convenient as a route to their final destination. God felt that it would be best to go a different route, however. The "land of the Philistines" at this time may not have been Canaan, but an area near Canaan.
The final note that is given for this chapter is the "absurdity" of God appearing as/in a pillar of smoke and/or flame to lead them through the wilderness. Once again, there is no explanation as to why this is absurd, so I'm not sure how to respond. Unlike many of the previous times something was called absurd, I really have no idea what the problem is here.