My theories are all leaning towards genocide of some sort. I wonder who the cats loathe the most? I know they get into fights with elves over ethics and the dwarves think they're dishonorable, they might think the humans are inferior and the goblins likewise. I could almost see some kind of relationship with the kobolds if they didn't have [UTTERANCES] and weren't vaguely dog-like. So, I'd say they're most tolerant of the humans, they won't necessarily complain about any of the cats' practices (I think) and they aren't likely to attack for no reason like the goblins.
That's actually pretty close to the dynamics I've observed. Generally, the cats wipe out any elven civilizations they come into contact with really quickly, since not only do the elves whine about the fact that cats don't tell the truth all the time, but they're also really tasty. Cats generally steamroll right over elves without too much trouble.
Against humans, they sometimes get into some squabbles but only over the eating of sentient beings - other than that, humans don't really care as much what cats do, and vice versa.
Against dwarves, the civilizations rarely come into contact but when they do, cats end up getting slaughtered. As in, I saw one war in Legends mode where battles with A: 19 dwarves, 2 losses, D: 173 cats, all lost, were pretty much the norm. Dwarves just don't like cats, what with the eating of sentient beings and the torture, and such.
But you'll see some of that in play...
As for your theories, I'm not telling.
Also, pretty soon I expect to have a lot more free time, so I'll be updating more I hope - that and I intend to put more effort into each update. I've currently played through the whole first year but only updated through Spring, so... I got a lot of material. Although, a good bit of it was a couple seasons of not much happening gameplay-wise, so I'll just have to make stuff up.