Maybe a change on the strings.xml? Xiaomi.eu use the translations of the week before, so if something changed there are crashes...
I rebuilt it yesterday, so with the updated and fixed translations I think
~ Xiaomi Redmi Note 2 Prime ~
It's translation not updated. Xiaomi.eu doesn't wait that translation communities updates his repos, so the latest features aren't translated.
Maybe applying translations with jbart can work (maybe, I don't know)
~ Xiaomi Redmi Note 2 Prime ~
If the icon pack supports Miui launcher yes... But for now there isn't icon packs that support MIUI launcher. Search on Themes app for icon packs for miui
~ Xiaomi Redmi Note 2 Prime ~
You have the latest MIUI ROM that isn't compatible. You need a compatible ROM, such as AOSP or CM, for now only AOSP is available. Check on XDA-Developers for it ;)
~ Xiaomi Redmi Note 2 Prime ~
You have to use an old miui rom (<5.9.15 If I remember well) or http://xiaomiredminote2italia.forumcommunity.net/m/?t=58244382
Xposed run, but some (a lot of) modules isn't compatible. There are some specific modules for miui.
Ps. Xposed doesn't depend to the device, but to the rom. That I...
It's on Deer ROM (a modified sMIUI ROM for Redmi Note 2, search on xda-developers)
Maybe if the developer tell us how he did it :)
~ Xiaomi Redmi Note 2 Prime ~