I am having the same issues that you had w my nexus. I unlocked the phone, got to the Bootloader screen stage, haven't been able to install the recovery and anything since I unlocked the phone. I am using a Mac laptop. The phone just keep boot looping, google screen...black..google screen....black....repeat repeat. What were you able to do from this stage to make it work? I am new to rooting, first time. FML. Please help me?!!! Thank you