A lot of that was done specifically to balance the game for a tabletop setting compared to a video game setting. It isn't 'wrong', it was purposely modified. Trainers involved in combat are generally optional rules anyway, because not every battle is league certified. If Team Rocket's trying to catch your Pokemon in a snare, I'd certainly want to know the proper rules for punching them in the face. The item changes likewise were done to help balance the game for a tabletop setting. You can change them to whatever you want, but there's a purpose to it. The -200% is in case you say fall off a cliff. Or accidently provoke an angry Salamance and fail your athletics check to dodge and not be stomped on. It's not that hard to get to -200% if you're playing a more gritty campaign. The x3 rather than x4 for double super effective is because with the hp calculations being what they are, if it was x4, a double super effectice move is an almost instant faint with no real chance of recovery. All about balance. Pokekon Tabletop Adventure stared at x4 and it was just too unbalanced, so they changed it.