There are multiple methods to attempt recovering the chromebook. Usually Reinstalling the os is a last step. if there is no firmware, os, or bios it may be the only option. I will post google links on Google recommended steps for reset and recovery. Reset: support.google.com/chromebook/answer/183084 Recovery: https://support.google.com/chromebook/an... The Recovery method will refer to trying reset first but the Recovery method uses the Chromebook Recovery Extension Utility on a chrome browser on a diffrent device and an internet connection and uses a storage device such as USB or SD card to create a Recovery drive. it will also ask for you to type the chromebook model you have or a selection that says select from model so you can select you brand and model pc. if the model is not listed google chomebook support may can tell you the correct image to use for your device.

Some cables are not sync compatible. If the cable is a generic cable there is a good chance that could be the case.

Yes. A bit locker recovery key will allow recovery and decryption of any drive encrypted with bitlocker or bitlocker to go. Most commonly this key will be printed, saved to a diffrent external drive, or saved to a microsoft, Active Directory, and/or Azure Active Directory Account. The Key should have the key identifier and recovery key listed.

was there visible jumper pins available for clearing the bios password?