Here is the guide to root Pantech burst
1. Download and place the Root Boot Image file in the ADB folder. It is the folder where you installed the ADB.
2. Connect your smartphone to your PC using the USB cable.
3. Open a Command Prompt Window in the ADB folder. To do so, right-click on any empty area on the screen while holding the Shift key on your keyboard, then choose Open command window here option.
4. Run the following command using the Command Prompt Window:
adb reboot bootloader
5. Your smartphone should reboot into the bootloader mode.
6. Now, run the following command using the same Command Prompt Window:
fastboot boot prestoroot.img
7. Wait for the Fastboot to root your smartphone.
8. Reboot your smartphone when it is rooted.
9. Head to the Play Store and download the Superuser app on your smartphone.
And coming to unlocking... If you have a doubt whether the phone is unlocked or not,Just go to the settings-general- where you can find what network your phone can support in the lock status.. other than that you need to unlock it.. But once unlocked you can use any carrier to it... If it is locked you can get it unlocked from any commercial vendors online like http://www.superunlockcodes.com
. where you just have to submit your IMEI number,country and network to them. further by the instruction they provide you yourself can unlock its step by step..