Okay, i keyed in the correct name but after my paypal checkout, it change my name to my paypal company name but those address and handphone number still the same.

so i requested xiaomi to change the name for me and they said it is not possible.

so  i want to know how is that possible that they can't even change a name?

i don't even request to change address or phone number.

paypal like to change ppl info, so double check before u pay by paypal with account,

I dare not simply install apps/ theme now.... 

From my past experience, though you uninstall the games/ apps/ themes, it will still kept some files/ folders/ something associated apps that I might not know (found out through usb plug-in and surprised that folders for uninstalled apps still kept in my phone). 

Worried this may eventually affect the phone performance or maybe it won't but I am not a very IT savvy person, instead of putting myself in dilemma of to delete or not to delete those files, got to think twice before install.