So I exchanged some mails with Michael Stapelberg of i3wm who rightly pointed out that my initial installation method of py3status was un-pythonic. I was not satisfied of using a bash setup either and I couldn't imagine a better opportunity to learn how to write a proper setup.py for my project.
Thanks to my Gentoo Linux packager experience, I knew what I had to do, so a few searches and tests later I'm glad to announce that py3status installation is standard ! I of course also packaged py3status for Gentoo Linux users : meet x11-misc/py3status on my overlay.
py3status being a real command and not a simple python module, I had to find the way to have setuptools taking care of this for me. I was happy to find out that this is pretty easy and that it works on both Linux & Windows, it's awesome !
I will explain all this in one of my next blog post as I'm sure it can be of interest.