BTW, can I change the language of the apps install into english?

after a few series of experimenting, i made a decision to clean install on the phone.

1- Using One Touch Upgrade S 2.8.0 I flashed the phone.

*Remove the battery for the entire process. Made sure that laptop could recognize the phone. (Win8 64x) Then i removed the phone again.
Open up the software, clicked start. waited till it ask to connect my phone via usb. Connected, wait for software to finish download.
at one point it will ask to remove the phone. so just remove it, and click the button in the software. "Upgrade" button if i'm not mistaken.
Then it will ask to connect your phone again, so do as it says. It will continue to install the fresh ROM into the phone.
It will inform for when the process end.

2- Time to setup my SD card. I follow the Tutorial
Once done with the formatting the SD card, put it back into the phone, put the battery and turn it on.

3- Rooting the phone.
Following the Mgyun method. Really. the easiest way. A couple of clicks, and done. It will install a Chinese SuperUser.
Tutorial by mR.hyDE
Might be a bit different from the pic because of the latest version of mgyun software. But it still work generally the same.

4- Download SuperSU from Play Store. Install, and open it up. does it ask to update binary? click yes, format type, normal.
See 3 tabs in that SuperSU? The Apps, Logs and Settings?
Click Setting, scroll down and find Install SuperSU into /system. hit on that.
it automatically uninstall the chinese version of superuser and all work as dandy. All english version now.

* Special case, Want to understand the chinese word when prompted for permission?
Explaination by bluehaze

5- Open up Link2SD app, and continue the setup from the previous tutorial for linking the app to sd.

Done.
Link2SD also capable to uninstall the custpack/app. aka unwanted software that cannot be deleted normal way.
that is also being teach here a few pages back. gotta go and find it yourself. Something about converting the custpack app to system app > to user app > delete.

All the best~