The picture only shows the visual appearance of the keyboard. A German keyboard is supplied, which has äöü keys.

Unfortunately I don't have a MacBook, but the keyboard connects to the laptop via Bluetooth. So I would say that if the laptop has a Bluetooth connection, that this will also be possible to connect this keyboard to a MacBook.

No, where the USB dongle is plugged in is also where the connection is. You would have to physically reconnect.

Unfortunately, these USB receivers are often uniquely coded by the manufacturer and cannot be easily replaced. It is best to contact one of our product experts from customer service to clarify all options 👍