I don't think cost of administration is a big deal. The outcome of the system in people's lives is more important. Otherwise you'll end up creating a system where people sit around in idleness and drink themselves to death on booze. Paying for their needs is a good idea, but what about using the payment to motivate them to make their own life better in other ways?
I think the costs of administration would exceed the payments. We're fine with bureaucratic jobs now because we need employment numbers, but those jobs aren't producing anything real. Look at the VA, it employs half as many people as the Army, just to manage benefits. What your proposing would, like the VA, require filings, delays, rejections, appeals and a whole lot of heartache. Simplifying things is the key selling point. You reduce pointless jobs that produce nothing and get rid of red tape in the process.
I just don't think adding bureaucracy is the solution. If I want someone to go to school I don't manage it on the individual, you'll spend half your money on administration. I spend it by subsidizing tuition.
Some people will drink themselves to death, but they already do that in our current system. How does that matter? The only difference I see is they'll have a lot more free time. Maybe they'll waste it, maybe they'll improve themselves.
