I just checked Gitlab’s website and it explicitly says “No credit card required” for the free tier. Maybe you registered for the wrong tier?
Looks awesome! I’ve been wanting to try openbox actually. To be pedantic, though, the icon is not ascii since it’s made from Unicode characters (someone had to say it).
You can run vim inside of emacs therefore emacs > vim
The license doesn’t really matter, unless you mean it should be included in the kernel. If it was another permissive license, you could also port it to Linux. I have no clue if it’s actually possible to port it to Linux natively, but I would guess that you can