I found a few minor errors in the in-game text:
When you type -commands, the full list of commands does not fit onto the screen. Perhaps moving one or two commands from the top line to the bottom line will make everything fit.
commands don't fit.png
Executioners have the role option "Invulnerable at Night" while other NI roles (such as the arsonist in the second screenshot) have the option "Invulnerable at night".
Invulnerable at Night.png
invulnerable at night 2.png
I found two typos in the night text messages. In this screenshot the night text says "Join our new clan to become part of the Mafia community and help! improve the gameplay!" There should not be an exclamation point after "help". Also, this message says "sc2mafia.com". The message in the next screenshot says "www.SC2Mafia.com". I don't know which is the preferred style.
night text improve gameplay.jpg
In this screenshot, the night text says "Donations are only run through the official websight www.SC2Mafia.com".
websight.png
Sorry if I sound bossy. I don't want to be a nuisance. I'm just trying to point out the ways that I think Mafia can be better. :-)