Here's a list of useful commands, dev console utilities, tricks, tips and hot keys I found that may be useful for web developers who got a coveted Chromebook outside the US.
Afterall, it's a device designed for the Internet and wifi connectivity of level California. It's quite painful to use it outside the tech heaven.
First of all it's possible to install Linux using a google app script (can work with limited internet VPN and curl) or using Cruchon, the later requires a download (not going to work in offline mode unless you download it into an USB drive before hand).
In Chrome browser command line utility can be launched with hot key Ctrl + Alt + T. This is called crosh.
Use Ctrl +Alt + Forward key to launch a full bash and the dev console. Dev mode must be enabled.
It's useful to have US wireless network and another USB drive, and a working computer. This way you can log in as a google user become the owner of your device, use the Chrome OS Recovery Utility (has to be downloaded onto a Mac or a computer and then the USB) , use the USB to reboot or recover a damaged Chrome OS.
A common error I got was webpage blocked or error enrollment checking pending. Basically all related to the First Run or the setup not complete and also Chrome OS doesn't connect properly to owner networks and wifi routers. I had problems using it with TP link routers.
A VPN build-in or VPN enabled router might work better.
In the end, there were several forced reboot, forced recovery (couldn't fully because the OS was damaged and I couldn't access a USB reboot), and finally a reboot upon post partitioning reboot and local data erase (thanks to a failed Ubuntu install), I can finally use my Chromebook as a guest and browse the Internet without any first run didn't complete nor enrollment error.
My plan is still to partition and install a full on Linux so that I can use the computer offline and online without having to go through google services which are not accessible in some countries or with limited connectivity.
esc + refresh
Refresh + power both can be used to access special screens and enable dev mode or recover. Ctrl + d to launch dev mode. Ctrl + l to launch successful Linux installation.
You can use VPN on Chromebook in Settings > Network > Add a connection > Add a private network. WLAN WAP (possibly more useful for android devices), mobile network (SIM card), proxy are also available.
Online IDEs are useful if you are logged in as a guest with no ability to save files locally.
In bash, the dev console on Chromebook, you can log in as chronos the super user or root with no password (until you set one). Being google and humorous. The user used to be facepunch, a geek speak.
Internet forums say Linux is the way to go if you use Chromebooks offline more than online. Chromebook also supports some online features upon successful completion of initial setup.
The first setup or first run experience was quite tough if not impossible outside the US.
Basic Internet browsing is possible without completing the initial run, but one cannot install google apps, extensions or 3rd party plugins without the initial signin.