The ideal number is zero. The safety net should be tied to the earned income tax credit, subsidized health insurance and housing, school and food stamps/vouchers - exclusively.
But what would stop a private business from offering employees $1 a day, noting that by working full time they will get all the paid benefits on your list? Wouldn't that just amount to the employer shifting their labor costs to the government and thus to the taxpayers?
No one would work for $1 an hour with even a medium basic income. That's only $2000 a year in a 40 hour work week.