| Quote #1
Although he was a yearling and still below full weight, he had not the harassed look of most "outskirters"—that is, the rank and file of ordinary rabbits in their first year who, lacking either aristocratic parentage or unusual size and strength, get sat on by their elders and live as best they can—often in the open—on the edge of their warren. (1.4)
This is a description of Hazel and, also, a sneaky description of Sandleford Warren. In Sandleford Warren, the ordinary rabbits get picked on and "sat on by their elders," which sounds not at all fun. So this is the home where Hazel and Fiver grew up—a home that only seems to respect size, strength, or parentage. Sounds pretty bad, eh?
| Quote #2
He had resisted all ideas of mass emigration and enforced complete isolation on the warren, thereby almost certainly saving it from extinction. It was he, too, who had once dealt with a particularly troublesome stoat by leading it down among the pheasant coops and so (at the risk of his own life) onto a keeper's gun. (2.22)
We don't have a lot of good things to say about the Threarah, but here we see how dedicated he is to Sandleford Warren as home. So at least that's something. He's so dedicated he'll even risk his own life (like Bigwig and Hazel later, risking their lives for Watership Down). It's kind of hard to hate a rabbit who cares about his home so much. But to be fair, it's hard to like him, too.
| Quote #3
[…] anyone seeing this has seen at work the current that flows (among creatures who think of themselves primarily as part of a group and only secondarily, if at all, as individuals) to fuse them together and impel them into action without conscious thought or will: has seen at work the angel which drove the First Crusade into Antioch and drives the lemmings into the sea. (4.1)
This long sentence is all about how flocks of martins seem coordinated when they fly. Those birds are just like groups of rabbits—and also like human Crusaders and lemmings. So this sentence points out how humans and rabbits can all be group-minded and oriented to the community, which isn't so great when everyone is passing around viral videos like "Gangnam Style."