The image in that video shows how the actual boundaries of time zones, as they are drawn by human beings, curve somewhat around various archipelagoes in the Pacific Ocean. This is not an astronomical idea, but a political one, meaning that the people who live on those archipelagoes wanted all the islands in their group to be in the same time zone for convenience's sake, which is why the boundaries of the time zones curve around them.

Is that all the video is about?

Pretty much, but he makes an interesting observation, one that needs proving. He claims the sun rises and sets faster in the southern hemisphere than in the north. A time lapse of the stars arcing around the south pole would be just as good if not better evidence of a globe.

To your first point, whether or not one is inclined to accept FE, there's no doubt but that FE has been aggressively censored by Big Tech.  As Matthew pointed out, there are no disclaimers about BigFoot videos.  There's SOMEthing they're trying to hide that's at least related to the FE issue, perhaps the overwhelming evidence of NASA fraud.  When has Big Tech been at the service of humanity, trying to prevent them from being ensnared in lies?

In FE model, whether there's an edge at all is unknown.  Firmament would "touch down", as it were around the edges of a circular region of a flat plane.  Hell is beneath the earth in the FE model, and you can see this in various diagrams of Hebrew cosmology.  This notion of an edge tends to be based on the idea of a flat disc floating through space, but the FE model (the most prevalent one anyway) doesn't admit of "space", but corresponds more to the detail about how the world is described in Sacred Scripture (kindof like below).  One of the things that won me over to FE was the fact that I find it physically impossible that the atmosphere would remain on the earth adjacent to a nearly-perfect vacuum (of space).  Gravity does not come close to explaining this, as it's an extremely weak force.  I don't believe in gravity at all, and the cosmology models based on gravity are what Kaku referred to as the greatest mismatch between theory and observation in the history of science, on the order of 1 with dozens of zeros after it (can't recall the number).  It's why they had to invent "dark matter", to salvage their cosmology.  If someone posited some kind of electromagnetic solution to the problem, that might work, and I personally tend to believe in the "electric universe" model (vs. gravity).