When someone selects the negative vote on one of our articles, it'll show a feedback container but I can't see how we can change any of the words in that container or where this is sent to (we're thinking of sending this to an external email address).
I don't think you can customise any of this. But comments do create a ticket with a subject starting with "Article Feedback". As far as I can see this is language independent. So you don't have many possibilities.
One suggestion: You could create a Dispatch'r rule to assign the ticket to a specific agent, and ensure that the email of that agent is the relevant external email address. However, that does mean the cost of an extra agent.
Or wait for FreshDesk to develop something ... Might be a long wait.