Yes. I believe you have to stay a year to keep the bonus, but everyone I know who graduated from Stanford last year was offered >100k salary, 100k signing bonus, and some stock (I think per year the stock was about 25k at current market value).

Even non-CS majors. If they studied a quantitative field, can code, and cleared the dev interview, they got that offer.

Yes they do. I believe for new-grads it was 50k if you were not an intern previously, and 100k if you were.

You have to stay a full year at the company otherwise you have to pay it back. But yes, it is all upfront; cash.