Guys, I'm new to Mi 3 here. Just got the phone like a week ago. Of course, if I'm new to the phone, I am new to the whole MIUI system as well. I find their theme system the worst. I mean, there are a lot of 3rd party themes out there which are awesome and I just can't install them if they're not from the theme store directly. I've read this on their forum, they said this is to protect the copyrights of the creators and all. I am not saying I have a better solution for this, but there are definitely solutions better than this. If you are really hoping to install a 3rd party .MTZ theme file, you must signup as the designers for MIUI themes, upload those you wanted to the store, and wait for approval and then only you can really get the theme you wanted working.

I am also having issues with NFC as well. I don't get it, I've enabled both NFC and Android Beam in the settings already. It just won't work, and I cannot understand what is going on.

To be honest, I believe there are a lot of people here like me. Really impressed with the hardware, especially for this price point. It is actually the software that ruins the phone, in my opinion. MIUI and its whole ecosystem are just plain not working well.

Edit:
This particular phone of mine, is all clean. I have not modify a single thing right out of the box, no root, no nothing.