usually the camera chops up the video to multiple files if they get to big. this has the added benefit that your recording is not totally lost when there is a crash.

i like panasonic cameras as they do not tend to overheat and i like the colors of the standard licture profiles. can you get an old gh5 or something?

like most effects there are multiple approaches, but generally, cutting out and animating the layers is how you achieve this effect. can be done i ae but also directly in premiere or other video editors. or even 3d software so you can create a convincing paralax effect