I don't think anybody has mentioned these things yet so I will chip in with a view to continued improvement in the future
I think you could use the services of a design specialist to improve some of your layouts, specifically use of text and paying close attention to the various scenarios the stream's information graphics could deal with. I felt like the overlay only did a limited job of keeping people up to date, I dipped in and out a lot and frequently didn't get a clear impression of the stage of the competition or status of the production. This could extend to enhancing and producing materials outside the stream as well. No disrespect intended to anyone doing this already obviously
Probably related to the above, a production basic that seemed to be missing was name tagging people on stream, I didn't watch the whole thing but the only attribution I saw was in the in-game hud. For a live production that isn't really the appropriate place when people are frequently on camera
The hud technology looks interesting and clearly has promise, but as others have said a lot of what seems to be CS:GO inspired stuff isn't really appropriate to TF2, although the suggestion to highlight unusual unlocks only is a good one. One area to look for other inspiration might be plugins or hud developments from the past that have been dropped for one reason or another. For example the team health bars were quite popular, and drawing attention to a medigun change or a possible spy play (not just checking in spawn) would be informative for viewers. Also the short uber bar baffled me a bit.
The various hosts sometimes seemed to be left with little clue what was going on and left to fill indefinitely. Although it's amusing to hear them calling for production aid once or twice it gives a chaotic impression after a while that goes beyond charming amateurism. I think by the end of the event you could hear it in their voices they had been left to talk a bit too much.
Nuze's sections were excellent - for me they were without doubt the single biggest triumph of the production, you should probably open a sister channel just for him. Very good decision to keep War away from the cock drawing technology