Cool post.
I've read through Option 3. I own all of the books but I'm not sure I care to finish them out. Frankly, everything past the original novel is a slog. I've posted this before but if people are looking for a series where it's all like book 1, you will be sorely disappointed. Messiah, Children, and God Emperor are much more philosophical treatise than anything. Almost zero action. Dune #1 is almost a bait and switch in that regard. And FTR, Dune, Messiah, and Children were a trilogy according to Frank. God Emperor takes place thousands of years after Children.
I've also read six of Brian Herbert's prequels many, many years ago. Again, they weren't that bad. People are so butthurt over those books. I think many that trash them like to play the card of being a Dune purist and loving the originals because of their very heavy intellectual and philosophical bent while the prequels are action space opera. Completely different focus and whether or not Brian usurped his Dad's notes I have no idea, but I enjoyed them for what they were....at least the six that I read.