East and west work fine if you use either the international date line or 180 degrees as the “edge.” Tbh tho, east probs wouldn’t be too interesting, it would just be Tokyo, maybe another coastal asian city, and some islands

You could use 0 and 180 degrees longitude

You could measure relative to the prime or ante meridian.

There is no easternmost point or westernmost point.

Of course there is. Just start walking westwards and when you can’t be bothered anymore that’s the westernmost point you’ve ever walked to.