Default [Q] Some problems with Android 4.2.1 device

I've a local brand android device with specifications
MT6589 (Quad Core ) ARM Cortex- A7
PowerVR SGX 544MP with 512m RAM . If somebody knows it is qmobile i have qmobile A500
For More specifications > (Rooted)

1_ I want to change the boot i searched Android AIO Flasher and in instructions there was written you've to turn FastBoot Mode but there is no fastboot mode neither in developers option nor in settings in 4..2.1.

2_ I've 512m RAM and like 160 is free always other is talken by system and i've one app Disable Service
what apps it said i turned off and got 250m free but it had one problem the notifications were lost but when i turned all services notifications restarted again. Now help me with what i turn off. I'll the names