Was X a rule at your school?

kind of - no eating anywhere outside of the canteen or the year group yards.

if you're late to the start of the school day for any amount of time for any reason you're automatically given an hour detention the same day after school.

No - we had three warnings then a lunch time detention

Not allowed to speak to teachers at lunch until after 1:20

Yes except it was 1:30.

Girls uniforms only permit them to wear white ankle socks or any dark coloured tights (black/grey/brown/navy blue).

No.

You can wear anything you like as long as it's brown or beige. (I have not worn brown since).

No,
Everyone on my school got hell lotta piercings

Not allowed to wear makeup to school

Yes - sort of - it got taken over.

Not allowed to have your clip on tie off.

I don't think so, although I have no students seen there in trainers.

Working in a group to a topic in a subject was a part at your school.

No - students had dyed hair and no one ever complaint, neither the teachers nor the students or anyone else.

Your class rooms were equipped with overhead projectors.

Yep

Going to the bathroom during class was never allowed

Yeah, unless you have a toilet pass

Skirts have to be knee length for girls (the teachers go on about this but no one actually cares)

Yes

There can be no main doors on the bathrooms only cubicle doors

yep
mobile devices from each class were to be collected and kept in a tray away from students till the end of the school

No...? (bit specific)

Not allowed to take shortcuts across school grounds/fields after dark

Nope

No closing doors too hard

No

Had a no blazer, no food policy (as in if you didn't have your blazer on you were not allowed to buy food at the cateen. I'm just thinking about this now and wondering whether this kind of policy is even legal to have).

Yup, and I only left secondary school last year so if it's illegal then my school are doing a bad thing lol

No talking badly about the school in public and online (seriously, this was a thing, they had us sign a whole legal document for it and everything, we very soon realised why lol)