- He actually starts to explain his reason for being there, but Riker and Picard cut it off due to being distracted by something else. There was no real explanation of why he was in Star Trek: First Contact either, other than the Defiant just happening to be at the Battle of Earth, and neither of these is mentioned on DS9.
- They should have simply had someone at some point claim "How can we be sure that the Son'a are telling us the whole truth? They've worked with the Dominion-for all we know, they may be trying to sabotage something with proven results for something tantalizing."
The Enterprise crew starts to feel the effects of the radiation the MINUTE they enter the Briar Patch, and Picard even says that it's all over the region. Dougherty just didn't want to wait to find it.
- Harvesting the radiation at all was unnecessary. You simply had to be on the planet or in orbit to receive the benefit. The whole evil plan pretty much came down to the Son'a, who were already so old and having exhausted all available medical technology to extend their lives that they could still die before the radiation de-aged them enough. So they wanted to concentrate the effect to be immortal.
The Baku have lived on the planet for three hundred years and probably built up a ton of those metaphysic particles in their bodies. The Son'a are the same as the Baku only really sick. Dr. Crusher could probably have the Baku donate blood or bone marrow (with their permission) and transplant it to the Son'a. It could speed up the healing process and help save their species.
If nothing else, it would explain why the Baku are identical to humans - that they were human colonists themselves. Similarly, the Son'a's appearance isn't a greatly exaggerated pastiche of plastic surgery and other methods used to preserve a youthful appearance, and their delayed reaction to the planet's atmosphere would simply be because of their advanced age.
- It's a stretch. By Sojef's timeline, they would have had to have left Earth about three years after First Contact, right when things were looking up for humanity after World War 3.
- And that makes it a stretch? Make it ten years after First Contact. That's not implausible, and nothing says Sojef wasn't a little off. They met aliens, traded for a better warp drive, and made it all the way to the Briar patch by circa 2075, about two years after they started.
- Alternatively, perhaps they discovered the planet before or during World War Three, in their efforts to escape the war and find a planet that could support life. It would also explain their reluctance to fighting.
- Warp drive was invented ten years after WWIII, and humans only had slower-than-light travel before then. Alpha Centauri might have been within reach in the 1990's, but the Briar Patch? No, it's supposed to be way out near Bajor and Cardassia, right?
- It's a stretch. By Sojef's timeline, they would have had to have left Earth about three years after First Contact, right when things were looking up for humanity after World War 3.
Come on! Even the Organians from the TOS episode "Errand of Mercy" put on a more convincing facade of a pre-industrial, agrarian society! The Ba'ku village is so perfect, so immaculately clean and white, that it looks like some sort of New Age vacation resort! The Ba'ku go about their labors with a casual ease that suggests that it takes very little effort to complete all the tasks required to maintain the village, grow food, make clothes and other goods. They come across as hobbyist "farmers" with a weekend home in the country!
There's also the standing question of how they kicked the Son'a off-planet and keep them from simply coming back. Granted, the Son'a show a lack of will to kill their kin, but it's a planet. Pick a scenic spot a thousand miles away and build a settlement of your own!
The Ba'ku know that they can score more sympathy for their "plight" if they pretend to be non-technological. So they conceal their technology to give the impression that they are a simple, rural people who should be protected by the Prime Directive.
- Farming is bound to be a whole lot less labor-intensive when your crops are kept phenomenally-healthy and vigorous by the same radiation that's keeping you immortal. They probably don't even have to plant seeds on a given patch of field more than once, but can just keep on harvesting the same perpetually-bountiful plants over and over.
- Not even remotely true. While crop failure has been a natural concern of cultures throughout history, until the late-20th Century there was comparatively little that people could do to control the growth rate and health of crops beyond keeping them irrigated and removing any obviously diseased plants. The majority of labor that went into agriculture came from harvesting the crops. Even then, what about things like clothes? Cotton plants that grow perfectly are great. But how does the cotton get turned into clothing? Lots of work! Same thing with building. Having good lumber available certainly helps. But you still have to cut down trees, cut the wood into required sizes and shapes, assemble things, etc... None of that kind of work is being accomplished by the planet's magic radiation. It does not build structures or clean houses. Indeed, an interesting question is whether it arrests decay of non-living materials and repairs the effects of environmental conditions like weather. Because an ageless human being could remain eternally youthful, but the house they live in will crumble around them unless the work on upkeep.
- Perhaps the technology rejection came later/gradually. They started off high-tech but were scaling down due to various cultural concerns/phobias/lack of adequate tech base. The faction that would become the Son'a wanted to use what tech they had to restart their advanced civilization, their elders said no, so they started a violent coup, got smacked down, were exiled and had all data of the Baku home planet wiped from memory (which given that it was deep in the Badlands, made it nigh impossible to trace back easily), then the Baku, horrified by what they felt they had to do, threw away what remained of their tech and went full Space Amish.
- And not for any moral but practical reason. Now the Federation have a whole planet they can easily turn into a second Risa for people to go to, study the effects of the radiation on people of various species long term, work on avoiding the clear degradation that the Son'a experienced from being away from the radiation for so long, as well as work on a way to replicate the radiation so they can make as much of it as they want. By contrast, the Son'a's plan could've just ended up destroying the only viable source of this miracle radiation in the entire galaxy.