I think that any kind of micro-management of peoples' livelihoods create poverty traps. This isn't just a matter of current first-world political systems: it's also observable in developing-world charitable activities as well. Check out the evidence from GiveDirectly[1] to see how an Unconditional Basic Income works better in environments that are entirely unlike our first-world political environments.

Basically, I think that people are really good at finding their own paths. It's what people naturally do, providing that they aren't structurally prevented or disincentivised from doing so.

And yes, I've seen the miserable rich-kid phenomena first-hand, and agree with you that too much privilege can be a real handicap. That's why I think it's quite important that an unconditional basic income be genuinely basic: enough to survive on without any privation, but not enough to be decadent on.

I've found a neat mechanism for appropriately setting the level of a basic income: 50% of the mean individual income. Here in the UK, that would produce a basic income of roughly £12k/year -- a bit less than working a full-time job at minimum wage. Enough to live a fairly decent life in a (now) impoverished Welsh ex-mining village, or enough to barely scrape by with a bunch of flatmates in London. But not enough to be extravagant on, in either case.

The nice thing about pegging the amount of Unconditional Basic Income to the mean earned income is that it builds in an automatic self-correction mechanism. If too many people exit the workforce, the mean earned income would fall, and the UBI would fall exactly in sync with it. As the UBI falls, people would be increasingly incentivised to re-enter the workforce. As people re-enter the workforce and the mean income rises, UBI would increase along with the inevitable increases in inflation.

1: http://www.givedirectly.org/evidence.php