To be fair, there are approximately 200 countries in this world. So you'll need data for about 200^2 = 40,000 different connections, and that's before considering subtleties like length of stay, PR statuses, etc.
Sure. I did say "more" rather than "all"; others have noted the absence of American in China. It'd make sense to prioritise some key ones before launching.
Information for Australians is at Smart Traveller FWIW, under Entry/Exit info. e.g.,
