You really ought to just read the books, but it's a LOT of "technically not incest" throughout the series. From the Bene Gesserit breeding programs, to Paul considering using his sister to make an heir, to Leto II's interest in his sister despite being unable to have sex, and then his breeding programs with the Duncan Idaho gholas. Nothing you can really call incest actually happens, but it's definitely uncomfortable at times.
If we're just talking pervert stuff instead of specifically incest, there's the thing from Chapterhouse where they "awake" the mind of a dead person they put into a child's body by the bene gesserit having sex with them. (This is a super old memory so may be misremembering specifics)
You're almost entirely correct. They clone individuals (gholas) and raise them in "tanks" which are basically women in a much worse situation than Handmaid's Tale. The clone in question was Teg Atreides who was the Bashar (General) for the Bene Gesserit. They normally awakened memories in gholas through stress but he was very young when they needed him to manage their forces. There was a suggestion about using sex instead which produced a long moral discussion about the use of sex vs violence. They went with sex and it worked.
I think it's not too far off at least. It was on their way to kill Leto II. and she quite liked what she saw.
Frank Herbert has quite a few sexual surprises hidden in Dune. I doubt they'll be shown in the movies....