As you should be. 
You can download a pre-built Jumpdrive image from Purism if you prefer but I would have to hunt up the URL.
To clarify … at this stage … it will boot over USB but not boot from the eMMC drive.
There are some promising signs that the phone is not completely borked.
Here’s approximately what your /boot partition should contain: L5 USA blocked due to an update! - #14 by irvinewade
I would say next step would be to telnet in to the phone.