I'm sure Dave Ramsey has never read Marx, and I'm equally certain he is proud of that fact, so how can he claim to know what Marx did advocate for or would advocate for? I'm not a Marxist, nor an expert in Marxian theory, but I have read and studied some Marx and based on what (admittedly little) I know, I don't see a connection between Marxism and universal basic income. In fact, I think Marx would have been opposed to UBI, maybe even viewing it as something that would strengthen the capitalist class and weaken the working class.
It is. Welfare states are perfectly fine expressions of enlightened self interest under capitalism. The owner class is guaranteed a relatively healthy population to exploit, the wage slaves are kept just happy enough to not rebel.