I don't have any problem with their mention of homosexuality - Baron Harkonnen is a villain who happens to have homosexual encounters. He is not meant to represent the gay community, so I think you are over-analyzing here.

Also, their culture is based off of certain features of human society on Earth, so that woman being in maternal or domestic roles is supposed to be indicative of a throwback to more "traditional" times. After all, this is a futuristic civilization that destroyed all of it's advanced robotics and artificial intelligence - a lot of the roles we see are actually supposed to be from the Orange Catholic Bible and it's supporting texts. You'll notice in future novels that after the God Emperor takes over, gender roles become more fluid and individual, with a generalized meta-evolution of the species being a realized goal of Leto II and Ghanima.

What I think you may be missing is that the book is written in such a way that it leaves a lot to the readers' imagination while a lot of action is happening on-screen. For example, in that last scene, we dip into the thoughts of everyone involved to see that Jessica's arrival was indicated in a prophecy among the Fremen - where you see clunky dialogue, I see a scene description from multiple POVs delivered in one chapter and rather fluidly describing movement and overall composition of the social scene.

Also, I think you are missing the fact that Frank Herbert wrote these characters with an understanding of Jungian psychology and archetypes - many of these characters seem quasi-mythical because they were meant to resemble myths.

You will notice that reading Jessica's critical paper on how the Bene Gesserit lost control of the Kwisatz Haderach project is a very different point of view from the tone used throughout the novel. This is because the point of view used to convey each story is largely different. I think "Chapterhouse Dune" would be more to your liking in terms of traditional POV descriptions - it is less about telling a story to an audience and more about the experience and inner motivations of a few core characters.