I love Lynch films and usually do pretty well picking up on what's going on but IE is by far his most cryptic. I couldn't understand why they show the rabbits when they show them. They seem to be just randomly tossed in there.

Yes. Rabbits reproduce rapidly. It is also true that the 'Rabbit test' was an early form of a reliable way to test for pregnancy. This movie is also at least about "a pregnancy", discovered and likely interrupted and its consequences. The Rabbit family dialogue seems random but they all talk about 'a stranger who is arriving' only the male and female Rabbits seem to have different attitudes towards this stranger's arrival. So a family, a stranger, a pregnancy and discord...that about sums up the movie.

We are seeing two forms of struggle.

The Rabbits struggle to deal with "evil outside forces" and "men in green jackets" and "dogs" in the Rabbits shorts we see this struggle but we see it as a sitcom where the father rabbit risks "hunters" to fornicate with other rabbits. Viewed as "infidelity" in the humanistic setting.

Inland Empire shows the struggle of dealing with the Hollywood Machine. The "evil outside forces" that are looking to use and abuse you. The "Men" that are at the center of all of these horrors. We are watching Nikki Grace (the rabbit) being essentially hunted.