A fair and thorough review, but in regards to the app list being alphabetical you said that there are no shortcuts to specific letters and that's not true. All the apps are grouped under their respective letters of the alphabet, and if you tap one of those letters you can quickly jump to a different letter. You can do the same in the desktop version of Windows 10.
You also mentioned that there are no Google apps such as YouTube and Nest, and it's true that Google does not produce official apps for Windows (because they're petty like that) but there are third party apps for both YouTube and Nest.
@vincent - You're right, I missed that about the apps. However, I would argue that an alphabetical list isn't the most efficient way to organize them - I wish there was the ability to create folders on a second page, where you could group apps the way you see fit.
And yes, there are third-party apps, but not for everything, so you can't be guaranteed that you'll get all the same features as you would if the company itself made the app.