Are there any regulations/rules that say you must play that champ in that role?

Nope. You can theoritically play any champ in any position so long as your intent is to win.

You can play any champ in any role. There's no such thing as off-meta champs go wrong roles (which doesn't even make sense). If you don't want to dodge, then just play it out. They don't always feed or lose their game. I've seen Janna top that murdered her lane, got first tower and go kill other lanes. What you shouldn't do is take the attitude that it's "some kid wants to ruin it" before the game even begins and you see what they are capable of. Focus on what you can control (your lane) instead of what you can't control (other people's lanes).

There are no actual rules stating you must play any single champ in a certain role... but if you were to play for example, singed adc with smite and teleport, regardless of how you do in the game/ regardless of the fact that you aren't actually breaking any rules, your team will most likely report you for inting/ flame you into oblivion. People take this game very seriously and because it's a team based game, having someone "test" out new concepts/styles of roles/gameplay is very looked down upon. Tl;DR no it isn't against the rules but i don't suggest you try shit like that :P

Here's the thing though. Off-meta things don't always fail. Typically a person who is bad at the game just assumes they can pull it off and try it out despite them A) Not being mechanically good B) Not knowing the champion well enough C) Not knowing their elo well enough and/or D) not knowing their laner well enough

The thing is, if you main a certain champion, I almost guarantee you can make them work about anywhere depending on the champion and rune set-up and everything. Typically though you'll get people that just go "oh I bet this'd work" on a champion they don't even play often. Like one they grasp, but aren't skilled with. It can work, and there's nothing wrong with it if they're actually trying to win, but if they are explicitly throwing on purpose and playing off-meta champs in off-meta roles with off-meta builds, then that's just trolling in my opinion.

Answering title question. No. But there are examples in history, when this case was banned. Check Nunu sup ban in best topic.

Are there any regulations/rules that say you must play that champ in that role?

No.

if there was rules about it then there would be no off meta. i have done MF mid several times with the occasional top and i can hold my own a majority of the time. i have also done Kled mid with mixed results. have yet to have success with Kled bot. i recently did olaf mid and bot and i havent played enough for certain results. so while it is dickish to go to different lanes than your suppose to there is no rule about it.

No, there are no such rules, but if you do something that is clearly unlikely to work, and then you play the game and it doesn't, don't expect people not to be frustrated with you.

Nope. I will continue playing anivia support and continue smashing people with it while my allies call me a troll or tell me im gonna try to steal their kills. Fuck off with that.