I'll stream of consciousness this a bit:
Wow, good voice and mic. You made sure to ensure it was well set up before starting.
The map and UI settings could be better set up. You don't have to follow my settings for placement of elements, but Core Selector and Economy Panel are useless when spectating (I suggest binding "/resbar" to a key combination to hide the default engine resource bar, I use ctrl+\). Hitting F10 a couple times to hide the menu bar is probably not a bad idea if you want to reduce space usage, but it's aesthetically fine to have. However, you are using Facpanel and Deluxe player list, which are very useful for spectating. Just make sure Facpanel doesn't hide anything in a way that requires scrolling, and Deluxe player list is the easiest way to show everyone's economy at once.
I suppose at some point I should get around to making a more dedicated spectator player list to replace Deluxe.
I'd also recommend setting map extension to show the texture and have curvature on and fog off. Fog is usually okay, but some maps (like Frozen Planet's urine yellow) have terrible edge fog colours. Don't worry about distinguishing the map from the extension, it defaults to being about half as bright, and that is configurable.
/mapmarks will hide map marks for the whole game.
You've got the excitement part down pretty well.
More UI stuff, but when I started I was asked to enlarge my minimap for the viewer's sake. It's not a bad idea in general.
Overall, you have a much better style of attention than I do for this game. A big problem I've always had is making sure I don't get too bogged down with every fight and exciting moment. In a game like StarCraft or Achron that's manageable, but casting Zero-K is like casting a fighting game. There's always something going on, so it pays to keep out of play-by-play except at truly key times.
The only other low-hanging fruit criticism is don't say "uh" or "um". I suppose if you are really trying to go for a very familiar tone it can work okay, but I would recommend getting out of that habit. When your thoughts end and you'd use "uh" or "um", just stop, breathe, and don't use "and" or "or" or "however" or anything else thinking something will be there after the word leaves your mouth, just stop, breathe. Then when the next thought comes, that's when you can use "and", "or", "however", etc. to keep it part of the same sentence, or nothing at all to start a new one.
Actually, in addition to the above, don't be afraid to pause and breathe for 2 seconds. That will help a lot to keep the commentary engaging.
Oh yeah, lower the game master volume a bit. If you use OBS that can be easily done by lowering the speaker input volume, as that is separate from microphone input. Maybe also increase the music volume a touch, though it's not bad as is.
Don't be afraid of descriptions, at least for version info and replay link.