Joey, congrats with your new job! During the Derby you mentioned that you might get some commentary gigs, and I am happy to see that your wife is letting you out of the dog house.
I have done some commentating for norwegian TV, and may have some input:
1. I hope you are two commentators in the box. If you are, you should try to adapt one role each - one should be the "expert commentator" who analyses the game and whats happening on the table, and the other one should ask the "stupid questions" and perhaps come up with funny stories about the players and "off table" info. That will give a nice interaction between you two, and certainly give the wolves in the chat room opportunity to come up with questions / comments.
2. Before the match, try to gather some non-pool info about the players. Since this is a stream, the people who are watching, are likely to be hardcore pool fans. If the run out is simple, you therefore need something else to talk about. Non pool info or details about why players aim / act / stroke in a certain / unusual way will surely be appreciated. (example: he holds his cue under his right ear because he is virtually blind on the left eye..- niels feijen) or (he used to be a macho dancer in a gay bar - I will not tell you who..)
3. Some times it can be hard to differentiate the colors and the balls from eachother. Its nothing wrong in saying: "The blue 2-ball next to the orange 5-ball"
4. Its OK to be quiet for 20 seconds.
5. Drink water
Good luck, you are more than articulate enough to do a very nice job.