That's just the price of the lens combo.
regarding the FPS. Have you edited Phantom Flex video before? It's freaking magical and hard to put into words when you start playing with speed ramps etc! I do, however, wish it had a bit more resolution but that's a ton of data to be pushing through the pipes.
because it's not about the numbers on a piece of paper. It's about image quality. https://vimeo.com/236861899
I'm guilty of cutting just about everything on the beat. However, I also learned to cut after an action and start a cut right at the action, thus highlighting that "point" you're talking about.
You had a GOP 4K camera in 2009?........
GH5 doesn't do 4K/60p 4:2:2 10-bit onto the memory card. It outputs that over HDMI but does up to 30p 10bit 4:2:2 10bit to the cards. 10bit 60p can be had at 1080p.