A Apple negou o uso de backdoors no iOS. Não poderia ser diferente.
Em um documento de suporte alguns dos serviços questionados foram explicados.
pcapd supports diagnostic packet capture from an iOS device to a trusted computer. This is useful for troubleshooting and diagnosing issues with apps on the device as well as enterprise VPN connections. You can find more information at developer.apple.com/library/ios/qa/qa1176.
file_relay supports limited copying of diagnostic data from a device. This service is separate from user-generated backups, does not have access to all data on the device, and respects iOS Data Protection. Apple engineering uses file_relay on internal devices to qualify customer configurations. AppleCare, with user consent, can also use this tool to gather relevant diagnostic data from users’ devices.
house_arrest is used by iTunes to transfer documents to and from an iOS device for apps that support this functionality. This is also used by Xcode to assist in the transfer of test data to a device while an app is in development. (traduzir)