People do not walk across antarctica all the time. Very few people claim to have walked across Antarctica, and most of the expeditions that do claim to have traversed across the entire continent really only crossed a small section of it when you look at their routes.
As for Polaris, take a look at your avatar. The whole sky looks like it is revolving around Polaris. I would say that this is more proof that the Earth is flat, not that it is round.
1.Enough people "have walked across, explored, charted and mapped Antarctica" to map an accurate map of it. The Ice Ring is mis-interpreted as the Ice Shelfs around the exterior of Antarctica and they aren't even continuous.
2. It is the rotation of the earth that causes the apparent rotation of the stars.
Please be advised that you are dealing with the Flat Earth Society who have no evidence of the Ice Wall. Even their "Bipolar Map of the World" shows "Antarctica as a continent" and the Ice Walll is explained since the rim of the Flat Earth is so far from the sun that the ocean freezes and prevent the ocean from spilling over the edge.
Also be advised of anything on this website is dealing with Flat Earth
? -vs- Round Earth Fact, although they are never going to admit it. Frankly the genuine view of most - excluding the Flat Earth Society - Is that this website is an embarrassment to the Internet.