Transparency amount should be user-configurable, with 2 sliders, one for Start Menu and one for Start Screen. User choice is paramount.
You can pin nearly anything to the left pane of the Start Menu, by simply dragging it there.
Your theme syncing "approximations" are wildly incorrect. They sync a lot better than you portray.
For your examples:
Selecting "Teal" on the phone correctly makes Windows 8.1 select...
Improved? I can no-longer immediately "Like" posts I see in the "What's New" page.. I have to wait 5+ seconds for an app to load. I don't know if I'm sold on this concept yet.
The final link at the bottom also says Beta, but shouldn't, right?
I wonder if it might make sense to have these "update install tries/logs" in the Windows Update area of Windows. That way, you could see when app updates tried to install, and when app updates...
File History backs up your Libraries. The trick is to make sure your SkyDrive directory is included in a Library. For me, I have the regular libraries (Documents, Photos, Videos) as directories on...
I think a combo sounds nice too, like "How to manage files with File Explorer and SkyDrive", and "Playing music with Media Player and Xbox Music"
For me, I cannot get one of the updates (KB2863312) to install properly.
KB2863312 will "install", require a restart, but then Windows Update says that the install failed, and the update is...
Here's another option that exists: Any live tile can be right-clicked to choose the option "Turn live tile off".