How I'd fix Windows 8.
#1 - bring back the full Windows 7 UX, the same UX you get when you install Start8 from StarDock.
#2 - during initial setup, ask the user if they want "Classic" or "Hybrid" modes.
Classic - boots into classic shell and you never see Metro unless you explicitly go there.
Hybrid - what you get now for masochists.
#3 - In Metro, make the search charm always visible. There are simply too many hidden elements in Windows 8 right now and search is something that you should always see.
#4 - Make the application charms bars always visible. I realize Modern = eliminating chrome but people need to see those commands. It gives a feeling of security. Once again I'd have a setting that would allow a power user to enable the current method.
#5 - Search, enable the ability to search against Apps/Settings/Files all at the same time instead of only 1. It's pretty infuriating that you have to select the Settings to search against it.
#6 - bring gradients, lighting and gloss effects to the tiles. Make the first party app tiles look pretty instead of ugly.
#7 - make the Bing apps fully functional. make the Mail fully functionaly. Fix Music app and so on.
Windows 8 brings so many more taps/clicks then you have in Windows 7. IMHO, eliminating chrome and not having visual cues worsens the UX instead of improving it. Why bring a new OS to the public unless you are going to make the UX 100x better then the current one?
There you have my beef, have at it.