See my post on bitrate. Your request for uncompressed is really for a higher bitrate (higher quality). For 24/7 recording the maximum recorded history would half each time the bitrate is doubled. E.g. 6Mbps would likely provide 12 hours on a 32GB card. A Blu-ray which also uses h.264 runs as high as 30-50 Mbps for video encoding (compression). So the notion of uncompressed is called RAW and you don’t want those terabytes.
I agree that bitrate for continuous recording vs live should be separate settings. However, my guess is that this uses a real-time, hardware based encoder and supports single stream. Therefore the live view and continuous recording engines hook into this and have to be the same. Even if this is software based encoding, it would double the CPU utilization and possibly be beyond the MHz capacity of the CPU. If this is indeed a hardware limitation the only way to implement this feature would be on a camera which would support two realtime encoded streams at different resolutions. This horrible audio may even be a limitation of a hardware based encoder with 8 kHz sampling, compressed audio codec. E.g. g.729a.