The SDK is a collection of stubs (none of the methods have an implementation), which is why the compatibility library exists as an add-on. The library does fall back to the native implementation on versions of the OS that support it for whatever you're using the library for.
Whether or not Android is "winning" has nothing to do with hardware reliability, which is the subject of this article. I'd personally like to see the reliability numbers broken out by OEM.
Right. This article isn't about who's "winning"; it's just a reminder that the benefit of hardware choice means that information is needed to make a good choice. Longer-term reliability information is more difficult to obtain than basic specifications, but it's still important.
Android isn't as closely tied to raw screen resolution as you'd think. The device is probably normal-hdpi, which would match most other high-end devices. I'd suspect most apps will work without any tweaks at all.