Yes, I usually do so at the end-of-the-year funding drive they always have between Thanksgiving and Christmas. The amount generally varies based on how much I’ve used it each year and how generous I feel, but I do think it’s a useful service, and I don’t want to see them having to resort to showing advertisements in order to pay their bills.
I wouldn't call it stock, but Italians do indeed use pasta water in many of their sauces. Makes sense because it's basically just starchy water, which helps to bind the sauce.
That said, you generally don't need more than one or two cups of it, the rest is still thrown out.
And that was actually one of the least weird parts of the game.