4) 'over the long run, it’s very hard to get a “good” job if you have been living on a basic income rather than working; employers do not like the signal sent by resume gaps' Economics would change significantly. If you wanted a "good" job and lacked the education and training you have the opportunity to pursue it on your own. I have a feeling there would be a huge increase in non-for-profit work (both in the traditional sense and in previously unseen markets), apprenticeships, and likely more internships (working for free at for-profit companies). I can't find any citation, but I remember recently reading about women joining the workforce significantly reduced the amount of volunteers for charities.

3) Politics would be very hard--but politics follow the people's will. If there's enough support, it'll happen (even if the transition is messy). I haven't seen strong, widespread support (or even wide knowledge of Guaranteed Income) just yet.

2) Admittedly, I'm not quite following the point. Society and government are the rules we all decide to make up and follow. The argument sounds very similar to politics, except 2) is convincing the people and 3) is convincing the politicians and people implementing it.

1) Cost is exactly why we're looking more seriously at this now (although, we may not be there yet). Ideally, it would be cost neutral or a net win to transition off of the quagmire of various welfare systems--similar to the argument for a flat tax rate. As a whole (speaking for the US) we're more prosperous and can afford to take on more of a social burden (or transition our social burden from various welfares to a simpler system). We're also moving toward a society where we don't need to have every person working to survive. I don't know if the statistics back up the narrative of city's factories getting closed and a majority of the population transitions to welfare and disability--while on the other side of the coin entertainment and the service industry are the largest growing markets.