I ACCEPT THIS HEADCANON.

@Joseph Raszagal  
I somehow see Gilda as being either a mechanics/auto shop teacher and Tirek as a Superintendent.

@FanOfMostEverything
 
Forgot about the Cakes doing that. Maybe they assist the school through vocational courses, that way Pinkie Pie could work at their store while still attending school.
 
Steven Magnet I can totally see as the drama teach. And, considering he’s a water serpent of sorts, the swim club bit works really well too.
 
Berry Punch teaching chemistry though… you’ll have to let my noggincanon work on that one for a bit.
 
Bulk Biceps I can see as that, but I’d still prefer Iron Will, even though he’s gotten far less screentime. It helps that he seems like he’d be a hardass and really put the kids through Hell, but at the end of the day he’s not an unreasonable guy.
 
The Crusaders would totally attempt to join every existing club. Can’t argue with that at all.
 
And Derpy. Dunno why I didn’t try to do anything with her myself. As such, I’ll completely go with what you’ve got for her. However, I will make her main game Risk instead. Surprisingly, she’s the town champ, though no one can guess as to why. Her play style appears completely random and she just seems to win all of her dice rolls as though it were her birthright XD .
 
Man, I’m having too much fun with this.

@Joseph Raszagal  
Sadly, we’ve seen the Cakes running Sugarcube Corner, so I think that one’s out. As for others:
 
I’ve always liked the idea of Time Turner being the Ms. Frizzle of history, teaching all the interesting bits that never make it into the textbooks. And, depending on how ridiculous you want to get, possibly going on field trips.
 
Discord I see as a physics teacher, or as he likes to call it, “Why we can’t have nice things.”
 
Berry Punch teaches chemistry. Explosions feature prominently on the syllabus.
 
Steven Magnet is a drama teacher… and the coach of the swim team. That mustache is surprisingly hydrodynamic.
 
Bulk Biceps is a terrifying gym teacher with a heart of gold. And more terror.
 
The Crusaders have attended every club on campus and are considering making their own.
 
And Derpy is the head of the game club. She has a mean chess game, but she prefers card games, both conventional and collectible. The girl has ridiculous luck, both good and bad.

Judging by the building’s size as presented in the movie, it reminded me more of an academy than an ordinary high school. If that is in fact the case, then here’s what I’ve got as per who the staff might be:
 
<Y> = Yes; already established in canon.  
<M> = Maybe; hints given, but requires more speculation.  
<D> = Dunno; either I’m, we’re, or somebody else is makin’ it up as headcanon! And there’s nothing wrong with that.
 

@Background Pony #5A80  
There’s no Sk on the periodic table, but other than that, it works. You can always use sulphur.

@Keith Mowz  
Haha yes! Those too!

He’s not Heisenberg yet. First, Pinkie Pie has to flunk out of his chemistry class and start doing drugs, then he will become the one who trots.
 
Also, RD is a better fit for Pinkman but I want Pinkie to be him for some reason.

@SJArt117  
And Rhythm Heaven. And Rhythm Heaven Fever.  
And now its time to watch this again.

I didn’t even notice it was him.

@CodeLuxor  
SKipping CLass?

Reminds me of Munchy Monk from Rhythm Paradise XD

So, is Zecora the friend that founded a successful company?

Wow… actually, with the all the fandom offerings, if he turns out to be the school chemistry teacher, or something, I’ll be kinda shocked, if tickled.

I thought he kinda already was
 
for the normal Equestria universe

He is the danger.

@Background Pony #E4D2
 
Same toupée

Your Eisenburro  
You’re goddamn right.

Can’t be. Too much hair.

I smell a spin-off of a spin-off.