Which completely ignores not only the other points I made but the market dominance Google has and their influence on other companies.
No, it doesn't. It answers almost all your "points", it's just that particular line was the clearest elucidation of the underlying crap your post was based upon. And pouring on more crap by suggesting that Google's "influence" with other companies has any bearing on whether they allow you to install third party applications they don't personally wish to support in any way is adding insult to, well, insult.
Point 1: It has no bearing on how strongly CyanogenMod advertises the possibility that their app might or might not void a warranty on whether it does, and whether Google should include software that does on a store that specifically exists as a way to ensure people can easily find apps that meet a particular standard. Google might have an obligation to relax those standards if people cannot use anyone but Google to obtain apps, but that's not the case, and further, there's little point in Google having a store if they don't enforce standards.
Point 2: Leaving aside the fact that you've conflated "damaging a device" with "voiding a device's warranty", again, this has no bearing on any issue here, given Google has no obligation to relax standards if its standards do not prevent people from being able to distribute software that doesn't meet them. As they can. Because Google has no monopoly.
Point 3: Already dealt with directly.
Point 4: Google is not "unilaterally deciding for all users" anything. Again, Google has no obligation to relax its standards if its standards do not prevent people from being able to distribute software that doesn't meet them. As they can. Because Google has no monopoly.
There's plenty to criticize about recent Google management of Android from a pro-freedom point of view, in particular Google's decision to encourage developers to rely upon Google Play Services (an API, and no, you don't have to use the Google Play store if you want to distribute an app that uses the Google Play Services API, so don't even go there) to avoid fragmentation, when the API is proprietary and available only to OHA members.
But Google has an absolute right, more so than Apple, more so than Microsoft, to ban apps from its store. And while I'd hope it never decides to go the Apple path and ban apps from competitors due to largely arbitrary anti-competitive criteria, a basic test of whether an app fails a reasonable set of rules - for example, because an app is likely to cause many users to lose the warranty protection on their devices - isn't just reasonable, it's desirable. Enforcing standards means Google Play has some value, rather than simply an unregulated marketplace akin to a back-alley in a red light district.
As for market dominance, at least stay on topic. We're talking about a free app. You don't need to get those from an app store. CyanogenMod just needs to add a link to the APK from its website. That's it. Does Google have market dominance for app stores for most Android devices? Sure. But let's complain about that when we see evidence they're abusing it. When they're using their dominance to actively prevent people from using things they don't like, not simply deciding not to support a particular product because of the potential of that product to hold Google liable for something not under Google's control, knowing that people who really want the app can get it and install it anyway.