Most federally funded welfare benefits are not available to immigrants, illegal or otherwise. This change was made in the '96 welfare reform act.
I think we should curtail the welfare, particularly federally funded, irrespective of immigration. I wouldn't use the existence of welfare to restrict immigration, particularly in light of the fact the immigrant populations are more likely to be working than native born.
I really doubt that, I taught school in Southern California for several years, I don't think you have a real grasp on reality there.