Well pointed out that 150,000 years is more than enough time for another civilization to rise and fall. My own idea was Atlantis, maybe a lost continent where those who rejected Lee's hippeeism made a society of their own. Eventually, they destroyed themsleves while the other survivors stayed alive elsewhere.
I agree with the idea of ditching the potentially unsafe ships. You wouldn't want one of those to explode and cause a fire you couldn't put out. Problem with keeping the Vipers and Raptors is they need to be refueled. I can easily see the people who have worked on those ships telling the rest of the fleet to go frak themselves and refusing to do anymore drilling.
Rejecting technology and some of the ships they could have used to build something is foolish I think. At the same time, the Colonials would have to deal with the fact that some technology and specialties would be lost. Take the brain surgeon who operated on Anders...that's a specialty that will be lost and no be able to replaced. With limited to no technology, who is really going to be able to replace Doc Cottle? A return to an agricultural societey would happen almost right away.