Between the Material You design and move to break apart the Chrome browser from ChromeOS, now more than ever, ChromeOS is Linux with Google's desktop environment.
You can install vanilla Linux, but huge headaches are involved.
I did it, and it worked, but I had to open is and remove a foil (equivalent to a jumper), go to developer mode, then flash a new bootloader by running a script from GitHub.
Think flashing a ROM on a pretty locked down Android device.
The upside is that when the process is done, you have a regular PC and no need to do any cumbersome process again.
Not even remotely. It requires custom firmware which often requires physical disassembly to install. From there you can install any distro, but you will continue to have many small issues and inconveniences often due to the nonstandard keyboard.
There was a Chromebook targeted Linux distro called eupnea that could be installed without custom firmware via depthboot, but it's dead now and the original repo got deleted after the Dev got hacked, so the build scripts don't work anymore.
Not really. A Chromebook to a laptop is basically what a gaming console is to a desktop pc. Yes, it shares a lot of hardware, and the ISA too these days, but even then a lot of it might be trimmed down without any notice, or on the software side, you might be locked into what you get. They did make it easier to install Linux flavors, bit you still get what you get