Nexus 7: does ruining the bootloader hard-brick the device? Or is there still a chance to recover? So, I've got a Nexus 7 and would like to start expirementing with images, etc (primary goal being installing Ubuntu in multiboot with Android, probably loading from a flash drive over an OTG cable).

My main concern (and hence the question) is: 

I've heard, that rooting, unlocking the bootloader and flashing ROMs involve some dangeorus operations (like "fastboot erase boot loader") that can render the Nexus 7 unbootable if something goes wrong (i.e. the bootloader ends up in a messed state or erased).

Is there always a strong guarantee (not "99 out of 100, I'd say, if you're lucky") I can get the Nexus 7 to boot an OS with software-only means (i.e. USB cable, PC, and my hands pressing the hardware buttons on the tablet) if the above-described scenario takes place (i.e. the bootloader is ruined and the device refuses to boot)?

I've discovered that there exist different opinions on that matter, with some (obviously quite experienced) people telling one should not really worry about possible problems during image flashing and alike operations, and still others seem to struggle with what appears to be a Nexus 7 hard-bricked after an unsuccessful flash attempt.

For example:


This thread is a story of several Nexus 7 devices (hard) bricked with essentially a wrong sequence of fastboot (or alike) commands.
This fresh thread bears an example of "a knowldgeble guy" telling everything can be fixed.


Please note: this question is specifically about Nexus 7, and not about unbricking in general!
If you can get the device to boot to fastboot then you can "fix" a brick. 

I have "soft bricked" my devices many times. 

Samsung has "Download Mode", basically their version of fastboot. If you have an image that you can flash, you can recover. The same goes for the Nexus 7. If you have an image, which google provides because they are "developer" devices (as well as consumer). 

The term "brick" is used very loosely and doesn't mean what it meant back in the WinMo days. When you bricked your WinMo phone it was as useful as a paperweight. 

The only true bricks I have ever seen is when something fails in the hardware. Anything else that I have seen there is still a way to get to recovery, fastboot, download mode, etc. If you can get in to any of those you are golden.