You should also be able to see a list of the previous chats in your analytics, instead of just the number of people that chatted.
You should also be able to see when in the VOD the chat was sent, and what the chat says. You shouldn't have to skip through entire VODs to see what the chat says. There should be a list that contains every single chat message you've ever received, and it should be accessible in the analytics.
You should be able to see every single chat message from all your VODs on the same page somewhere in your analytics, and there should be a way to know which VOD that chat message was on.