I would expect that many local shops keep them in supply, and you are also able to get a subscription to them, though I am aware that if you are in search of one, you likely do not have a subscription.
That does sound like an order I have heard, and also quite a mess to make. I do not understand what ‘half foam’ even means.
Stellar guess on that last part. I’ll check around.
Who knows. It could be half the cup is foam which seems like a waste. Or half the normal foam, whatever that is. I drink my coffee black so fuck if I know. People should just order a milkshake and call it a day.