Disagree on several points. Most notably, while the word foul has regrettably fallen into disuse, I think the distinction remains: a player may only foul an opponent, but may commit misconduct against an opponent. Thumping a teammate cannot be a striking foul. But it can be misconduct (USB or VC).
I agree that PIADM can be predicated on danger to oneself or a teammate, but to be an offense (unless it rises to the level of misconduct), it has to unfairly impact an opponent. And it's not possible in the scenario in the question, as the the opponent of the GK is precluded from playing the ball--until the knucklehead kicks it away from his GK. That is not a PIADM offense. Is anyone seriously going to give the opponent a FK because an over-enthusiastic full back kicks the ball away from his own GK?