According to the end credits, Jennifer Giles as Capt. Jen Simmer.
In IMDB, William Tokarsky as the Killer is credited as "Bill".
In a meta-sense, almost all the actors' names given throughout the short are their own, not made up ones. Yes, even Gwydion Lashlee-Walton's.
Deleted Role: Comparing the end credits with the rest of the short reveals a handful of missing characters such as Jonathan Jackson as Juggler Cook, Rachel DeJulio as Chloe Bush, etc.
No Budget: Possibly, and probably part of the joke. [adult swim] has not divulged the full budget, but it's known that it was five figures and equal to that of their other parody infomercials. Almost all of the actors were from Atlanta, Georgia and paid the bare minimum. A lot of the scoring, editing, and FX were done as favors to the creator. Several of the sets, like the hospital set or police briefing room set, consisted of just a wall with props set up on it.
Orphaned Reference: As mentioned above, some characters had their scenes cut from the final short, but a slight few of them do briefly appear in other shots. Two actors, Aurangzeb Haq ("Roy Broil") and Tony Holley ("Sebastian Cook")note Whom, unlike the other characters backstage who are frozen, is seen freely walking, possibly suggesting that hes an In-Universe staff member on the shows production team., appear backstage when The Killer is chasing Samantha Cook, while two other characters (a new police officer and a woman in a yellow dress) turn up snogging with T.L. Cook and an alien respectively, when everything goes out of control.
Shrug of God: On his RedditAMA, the director of Too Many Cooks was just as uncertain about what the short means, and also left it vague whether Smarf managed to push the Big Red Button before he died.
Spoiled by the Format: While much of the short's popularity has come from being viewed on the Internet, knowing in advance from the playback bar how long it's going to last does lessen the effect of some of the jokes, especially the very brief appearance of actual show before the sudden appearance of the end credits. On the other hand, the original TV run put a pretty major spoiler right at the beginning: TV-MA V.
Throw It In!: The looping mansion-to-falcon clip originated from a playback error, which the creators decided to just leave in.
Due to uncertainty about how many people would see this (remember, this short was scheduled to play at 4 am), the director considered putting in arrows to point out the Freeze Frame Bonuses of the Killer in the background.
There was more of the last scene filmed, but the creators decided abruptly cutting to the end credits was funnier.
The actors' names were originally going to be made up ones, but they ended up just posting their real ones.
There was going to be a Stinger with a promo for a different show, Two in the Bush starring Chloe Bush, but it too was cut.