About Teemo mid support
Gotta say i tired it in few normals and works really well, dont see why would be a bannable thing, If you consider it worth banning you should do as well with karthus nunu and taric yi strategy, since you will not have the entire game a midlaner and insead just a jungler permanently taxing everything, but in teemo case you dont lose anything to have 2 supports insead, you just got a support placed somewhere else on map, without losing any resource, and if your adc is not stupid enough to push in a 1v2 situation then there wouldnt be problems in lane phase to just freeze the lane, and i will try again.
I honestly think to do even a mobafire guide once i manage a little bit the optimal build for that strategy and give it a try in rank (considering riot is stop trolling and not just blindly ban any teemo like they do when a nunu have a certain summoners spells)