Feedback on your (very good) comments:
Right now, at some events, someone has to "ferry" the chat room questions to the announcers; they don't always come in on devices in front of us. I assume you'd like all of the announcers to have chat room comment access to facilitate two-way conversation?
Re the "poll the viewers, who do you think will win?" we could do that at the beginning of a match when there's just one match that we'll be following at that time. Earlier in the broadcast, when there's more switching between matches, it's less practical.
Do the viewers want us to poll them re which match to follow? Start with one of our choice, then switch if possible if there's a consensus? That does pose the issue of "broadcast for now" vs. "broadcast for posterity," though. The match live viewers most want to see may not be the best one to archive.
We use the IFPA profiles to identify the home states and significant accomplishments of the contestants, but it's done now on an ad hoc basis. One bit of data most sports have that we don't is the head-to-head records when it's a two-player match.
Play-by-play vs. "drifting" focus varies a lot; some folks like the side chatter more than others, too. In the booth teams I've been on, we've tried to include the "how" with the "what," but like anyone, sometimes we succeed better than others.
Announcing takes practice, too, and pinball announcers don't get that many chances to hone their craft yet. But we try, and appreciate your indulgence as we learn.
Can't help you on the advertising the streams angle; that's up to those providing the gear.