I accomplish most of these requirements in Office 365 by using mail flow rules. It seems that G-suite has the same type of thing called routing. Read this article from Google. https://support.google.com/a/answer/6297084
You should be able to use this to filter incoming and outgoing emails by attachment file types, content, etc. If they have regex, I would recommend learning regex so that you can filter with regex to remove phishing links that hide what they are using regex such as this
You could also use regex to detect social security numbers, credit cards, etc.