I completely missed that this phone was rooted. Try doing this for a factory reset. Turn off the phone then pull the battery and put it back in. Hold volume down+power.
This should get you to your bootloader. From there use the volume down or up keys to navigate to recovery. Select with the power button. Once in recovery, you should find in there a wipe menu.
Depending on what recovery your phone has, you may have to navigate with the volume and power buttons or it may be touch screen. See if you can find a wipe menu in recovery and find an option such as wipe data/factory reset.