@hawkeye10,
Hawkeye, I once punched my dad, I was living with them after having lived alone for a while, and was opposed to corporal punishment. He was fighting with my brother and I ran down and told him that if he smacked my brother again I'd sock him in the face. An "Oh yeah!?" and a half-hearted smack later and I had to live up to my threat. Being physically able to was the least of my concerns, it was hard to do even though I had no physical fear of him.
It happened to turn out well, but I did very nearly get kicked out of my home again for it. My dad's reaction was just "get out of my house!" but my mom said if I had to leave again she'd go with me, they decided to talk it over and concluded that they'd abandon corporal punishment and that I could stay.
That, for me, went as well as it could have possibly gone. And it was still very difficult of an ordeal with a lot of potential to not go well. And the physical size had little to do with the challenges. Hell, it's a lot easier actually to attack your dad knowing he's gonna take you. It's harder when you know the opposite, and have to live with the results. I think you are advocating physical conflict, which has many more dangers than just a physical beating, very irresponsibly. And to someone whose situation you know precious little about.
Let us at least say that the "punch your dad" solution should be taken with a grain of salt. It's not often that it actually resolves a situation, even though I was lucky enough to have it work out it can go profoundly wrong. I wish you'd think a bit more about the potential harm your advice may cause in these situations.