It could be too big recovery install with fastboot causes problem, every recovery cwm/twrp i tried to install with fastboot fails.
Download vocoderisms TWRP build, extract "recovery.img" from it.
After you have kitkat installed and working:
Option 1, use TWRP without install:
Boot to bootloader (adb reboot bootloader), boot twrp (fastboot boot recovery.img) and install rom from there.
Option 2, install TWRP (have not tested):
Upload twrp zip to phone (adb push Twrp_MotoG_signed_010814_163615.zip /sdcard/), boot to bootloader (adb reboot bootloader), boot twrp (fastboot boot recovery.img), install Twrp_MotoG_signed_010814_163615.zip.