well, I managed to get one of the water streams down to the lava. The lava changed to ingeneous rock. To the lava lakes on the upper pictures I could not dive. Too deep… It just seems like water and lava touch each other but the lava still stays lava.
The prices for one item is 5C but when I put 2 items in the selling basket the prices written is only 9C
Not sure if it’s a bug or not but it is quite strange. (Was on Tel II at the hanging village (around 1500, ,-1270)
Maps are square but each side are connected, so you could do a round-the-world by walking continuously on the same direction. And as @Heureka says it seems to be a sphere because the square map is deformed. (There is a post with a graph to explain it somewhere in the forum)
I found this when I walk far away from my beacon and it appear on the compass in front of me. So the border is just like on earth nothing change but your coordinates.