Genesis 35 is a bit of a hodgepodge of tying up loose ends, telling of the death of Isaac and finishing the part of the story that focuses on Jacob/Israel. Let's see what we have here.
God tells Jacob to go to Bethel, the place where he had that vision back in chapter 28. At that time, Jacob called the place Bethel, and here he seems to be naming it that again. I commented on this a bit back in chapter 28, but something I failed to mention then (probably because I missed it) is that the name Bethel first comes up way back in chapter 12. I'm actually a bit surprised that the SAB fails to note this, as it did note some similar things elsewhere. Putting all of this together, there are a few things I can say in addition to the comment that this was a personal name only Jacob used until now. The fact that Bethel is referenced back in Abraham's early days suggests two things, one or both of which could be true. The author of Genesis may have referred to certain places at times by names they didn't have until some time later, simply for the purpose of making it familiar to the audience at the time it was written. Whatever Abraham called Bethel, the readers probably would not recognize that name. The other thing is that despite the fact Jacob apparently originally names Bethel, God, having omniscience, already knew that that was the name it would have, and had always called it that. In any case, it's clear at least God knows the name before this naming, as He refers to it by name both in the early part of this chapter and in chapter 31.
Before going to Bethel, Jacob persuades his family and perhaps servants as well to "Put away the strange gods that are among you..." This involves throwing out any idols (such as the ones that Rachel has hidden, perhaps) as well as a number of items of jewelry that apparently have some sort of pagan connotation to them. Jacob buries them, and then as they travel, the Bible tells us that "the terror of God was upon the cities that were round about them". The SAB marks this as "cruelty" and "injustice", but gives no explanation as to why. It seems to me that the simplest interpretation of this verse is that the people in the area are still aware of what happened to Shechem and his people in the previous chapter, and knowing that these people are apparently fully dedicated to God, they fear God indirectly through fear of them. Of course, it could also be some sort of supernatural intervention on the part of God, but it's hard to say, and I'm just not clear on what makes this cruel or unjust.
Once again, God appears to Jacob, and once again, the declaration is made that Jacob will be henceforth known as Israel. Both of these are issues for the SAB, and issues I've touched on before.
Shortly after this, Rachel goes into labor with her second and last son. She dies in childbirth. The SAB says that "...in the Bible, a woman is expected to die happily as long as she has a son." I'm not sure what this is supposed to imply (perhaps this comment is an allusion to a possible alternate phrasing of the translation which would mean the midwife is saying essentially, "I know you're dying, but on the bright side, it's going to be a boy!") but there is some truth to it I suppose. In the ancient Jewish culture, for a woman to have a son was indeed a matter of some prestige. Nonetheless, as she died, Rachel names her new son "Benoni", a name which means "son of my sorrow." Apparently, the name doesn't stick, as Jacob prefers "Benjamin", which is the only name he's referred by ever again.
A while after this, an episode occurs in which Reuben sleeps with Bilhah, his fathers concubine. It's not really too clear whether this counts as incest, as Reuben's mother is Leah, and Bilhah is even the handmaid that was having children to be credited towards Rachel. The fact that it was Bilhah and not Zilpah is probably significant, and apparently the Talmud suggests that Reuben is trying to do a favor for his mother in making sure Rachel will not be able to even have any more children through her handmaid, since Jacob would not be likely to sleep with her after this. Another idea which seems a bit more likely to me (partially because it's a bit more Biblically based) is that Reuben, being the firstborn, is hoping to exert some sort of power grab. Jacob has, in many ways, become the king of a new nation called "Israel", and Reuben is theoretically in line for the "throne". In those times, when a king conquered another king, the conqueror would take the old king's concubines for himself. Whatever the nature of this very wrong action on Reuben's part, Jacob, as in the story of Dinah, is not recorded as having a reaction (at this point in time, but see Gen. 49:3-4). Jacob doesn't seem to have any more children from any of his wives or concubines after this time anyway.
Finally, after all this, Isaac dies, at the age of 180. I'm still not at all clear what is so absurd about these advanced ages. Granted, they seem unlikely, but I don't even see that a miracle is needed to make someone live a long time.