You can use the chat to communicate with others in a respectful (read: neutral or positive) manner, but you've gotta know when to just mute someone and move on. The people getting banned for chat-related offenses are the ones who are using it just to be verbally abusive jerks to other players (not just for calling people bad or a troll or calling for reports). Not only that but they did it consistently to the point where they used up all their chances to reform and got permabanned.
I myself use chat quite a bit and have never been warned nor banned. How? Because I don't do or say things that I know will just tick people off. Next time ask yourself "Is this helpful, respectful or constructive?" If the answer to that question is no then just don't press Enter.
tldr: The chat-related permabanned cases commonly consist of people using it just to verbally abuse & harass other players, and these same players have often ignored all prior warnings as well. If you want to use the chat then use it for things that are helpful, respectful and/or constructive. If what you type isn't any of those things then just don't press Enter.
