That isn’t really something that Customer Support would be able to provide. The majority of what our teams look for in their investigations are kept secret to avoid folks abusing that information.
That can be a factor, yes.
No, investigations may happen from reports. There are no automated bans for afk/non-participation.
The report/debuff system is based on your fellow players reporting someone as potentially afk/non-participating. Those reports can also initiate follow up investigations, but that is not the only thing that causes our investigation teams to look for potential policy violations.
The penalty is usually set to dissuade repeat violations, beyond that, Customer support wouldn’t be able to answer any specifics.