I'm pretty sure that's the definition of cheating
To me, this question reminds me when people say that they personally never break the law, but if you ask them, they of course break the speed limit in their car all of the time.
I disagree. The purpose of that rule is to prevent a player from sharking their opponent by conceding some game balls and not others. Under those rules, a player that concedes a ball then doesn't forfeit the following game is cheating. Personally, I think a better rule would be that if you concede a ball at any point during the match, you automatically concede all subsequent game balls during that match, no matter how difficult the shot.
I agree in general, but there are some very specific exceptions - like taking an intentional foul in one pocket.
I think you are mixing up the definition of a "legal hit" and what it means to follow the rules. Making an illegal hit and applying the appropriate penalty is still following the rules, therefore it is not cheating. It's the same principle that applies to intentional fouls at the end of a basketball game: the team doing it isn't cheating, but they get penalized in the form of giving up free throw opportunities and having players foul out. Sometimes, it's still a viable strategy, despite those penalties.
It would have been cheating to take advice from a teammate then continue to shoot. You didn't break any rules, but I would consider what you did unsportsmanlike since it violates the intent of a (poorly conceived) rule. Also, even if it was a legitimate use of that rule in your league, it was unsportsmanlike to take advantage of an obscure rules loophole without informing your opponent of what the penalty was.
