Re: Warnings and suspensions over time
Typically getting actioned for saying something like that isn't the cause of an automated punishment system that detects hate-speech.
This means that a player reported you, Agents typically act based on what players don't find acceptable.
I personally also think saying "idiot" isn't really a big deal, though it's possible others take offense to it.
EA Agents don't have the context behind the situation, so they just act in such a way that it might benefit the community.
Do note that Agents typically have access to your chat logs, so future agents might be able to see what caused your ban.
So if you get reported in the future and they see that, they could decide that it isn't important to the current case and dismiss your history.
I also understand your concern, my best advice would be to just leave chat alone or hold yourself back from saying anything that could be offensive.
Do note that the action taken against your account could've been for something else apart from saying "idiot" unless the agent said it themselves.
Also as I am writing this, I realised that there can be a lot of offensive synonyms of idiot.. of which those words aren't really that hard to avoid saying.
I'm not going to mention these words, though they can have some impact on others.