I would rather create a modular camera similar to the FS100/FS700.
Sell the body for 2000 to 2500, with add ons for simultanous 4K recording, professional audio (XLR) for 1000 each.
I agree with 10 Bit 4:2:2, but at a price point of 4-5000 as a complete package would that really be enough to stave off Blackmagic with their BMCC?
Why not raw?
Besides ergonomics I would advise Panasonic to create a whole new noise free low lighty sensor with large pixels and a native resolution of 4K for clean downsampling to full HD with some extra pixels for inbuilt image stabilization. And yes, I know, Panasonic builds IS into their lenses. But a cinema camera would need to operate with a lot of adapted manual lenses which would need IS badly.