I don't really know much (or really, anything) about economics or the viability of these sort of social programs, but in the highly hypothetical scenario that every citizen received a basic income, wouldn't inflation quickly become an issue? Like I said, I don't know shit about economics so maybe that wouldn't be the case at all. It just seems like such a good, simple idea but I don't really know how well it would work on a larger scale.
Depends on how it is funded,and the state of the economy. If it is funded by printing money, it could result in inflation. However, if the economy is experiencing deflation, as Europe is now, it would reduce deflation. So the answer is preventing inflation is a balancing act. In the USA, the federal Reserve has been printing money to buy assets from big banks (QE) in order to combat deflation, but without causing inflation. They have succeeded.