SEO doesn’t mean that the site pays Google. It’s exactly the opposite. SEO means gaming the Google ranking algorithm to appear higher in the organic rankings without paying Google. In the past, people would do this by creating link farms to game the page rank component.

Supporting apartheid has nothing to do with antitrust. In fact, there is no law against it at all.

Google does not “throttle access to sites that don’t pay them.” Paying for an ad placement is as old as newspapers. There is no evidence that they additionally down rank sites that have no advertising account with them, and it wouldn’t make any business sense anyway because having nonpaying sites rank highly is what convinces a paying site to pay more to get top of page ad placement.

Welcome to 2010. https://android-developers.googleblog.com/2010/06/exercising-our-remote-application.html

Remote installation via the web has been exposed to the user since 2011. https://googlemobile.blogspot.com/2011/02/introducing-android-market-website.html

This also means users can remotely uninstall. https://www.androidauthority.com/google-play-store-uninstall-button-3614548/

Yes, it’s possible that Google will abuse this, but it would be an easy antitrust case.