You're quite right. We're working on a demo setup :)

FYI though - yes, you can choose whether to collect billing & shipping info at a per-product level.

The buyer and seller both get notified by email (and if you have the Stripe app as a seller, you'll get a push notif). The charge gets fully logged in the seller's Stripe account, with all metadata (so if you ever disconnect Trolley you don't lose anything about your customers)