Unhappy [Q] Help Please ! ZOPO ZP600+ problem :(

Hey guys
I'm totally new here and nearly a complete noob !
I got a ZOPO ZP600+ 3D phone with android 4.2.2 and kernel version : 3.4.5
Chipset is MT6582 Quad 1.3Ghz A7 with Mali400MP2 @ 500mhz ( I guess ) and 1GB of RAM

I have a problem( with the phone of course ! ) that is messing with my mind

I think its related to 2D rendering
all of the launchers are slow and they're not smooth . they're even slower than a simple dual core phone !
the default live wallpapers are running on slow framerate and laggy (somewhat near 10~15 fps)
and I tested a 2D game called "Line Runner" and it runs like slow motion !!!

I don't know what the hell is wrong with my phone .
I flashed a custom rom ( have exposed framework by default) and changes some settings and tested some exposed options but had no luck fixing the issue
I ran V6 Supercharger script but still didn't fixed it

force gpu rendering on developer options didn't help

I don't have any problems with 3D games and my antutu score is ~17400

( Rooted , Custom rom , Xposed installed , CWM Recovery )

please help me ;( , what should I do to fix this issue ? Its really driving me mad