I'm not sure if shadow banning is a thing but it's possibly because you've used a phone to connect to the internet and someone else has abused that IP address in those boards.
As far as bans are concerned: Sure drunk posting to strangers can be fun but is it really worth risking a ban. So long as you abide by the rules of the website banning shouldn't be a problem.
At any rate, welcome to VIP. How long will you be staying?