Eastern Asia

4 times as big gives better results but can be a pain on smaller monitors.

Working on an image 4 times the size, you can use a 25% zoom and it would look normal size, then after resizing, you can go back to 100% zoom.

As Matty & Vexer suggested, making the image Two or Four times bigger would give a good alternative for smooth lines if the tools aren't available.

This map could be called "China", as it is primarily a map of China.

I have highlighted the boundaries for clarity:

It's a bit pointless campaigning to change the map name just because it holds the whole country of China, it still holds other countries albeit not all whole, however it is still as much Eastern Asia as it is China.