i know this reply is late but it might help others. the solution is simple, since you said pdanet can detect it and so apflash tool there no problem with the rom. its just that mt6582 devices running kitkat 4.4.2 needs higher version of adb so you just need to do two things download an mtkdroid with adb version 1.0.32 bcos most mtkdroid tools had been built with adb 1.0.25 so this detects the devices as offline. please dont replace the adb in the mtkdroidtool folder it wont work then after that you have to exit pdanet from notification tray, you are set to go.
i need to add this if you come across some silly two silly errors while backing up your device. first download and install stericson busy box manually then proceed. Note that most of this rooting softwares super users do not match with mtkdroid so you'll need to download super su from playstore install and update binary then you are good to go.