No, its not a house rule at all. The rules don't say one way or another how you have to set the stakes for particular conflicts.
You're right, they don't say anything at all about "setting stakes." They give pretty clear rules on how conflicts work and I don't see any division keeping social attacks from being used in any conflict. In fact:
Keep in mind that not all attacks are necessarily physically violent—a particularly persuasive argument, lie, or distraction can be considered an attack if it directly affects the opponent. Social attacks are appropriate in situations where the action contributes directly to removing the opponent as a factor in the conflict.
Its no more inconsistent than my understanding that you can't use fists in the middle of a debate without some kind of change in stakes.
You keep mentioning the "stakes" as if every conflict has only one issue going on at a time. That's not the way the book states how conflicts are constructed. Conflicts just aren't that clean cut. In a conflict, many different issues can be trying to resolve themselves in many different ways. Someone who has begun to attack someone can still succumb to the defender's pleas of mercy and let them go, the pleas of mercy being a Rapport attack which the physical attacker was taken out by, or possibly conceded to.
I think the book even references the classic "My name is Inigo Montoya" scene from Princess Bride, a pretty clear example of someone using Social attacks to force some Consequences on someone before taking them out physically.
If you are in a debate, the stakes are to convince everyone that you have the better argument. Punching the other guy would be effectively a concession of the debate, because that is clearly an inappropriate method to "take out" in the given context.
Well if you do it stupidly like that. There are always going to be bad examples of attacks of any sort, attacks that don't make sense. Even then, I don't think it would necessarily be a concession. It would simply be switching stress tracks. Ending a conflict by taking someone out doesn't necessarily mean resolving the issue that started the conflict. In this case I would argue that the debate was interrupted by a fight and never finished.
The stakes of a fight are typically implied to be standing when the other guy goes down. If those are in fact the stakes, then intimidation can give circumstantial bonuses (i.e., maneuvers) but can't give the final result.
You're still talking about "stakes" as if it is a rule. Yes, it makes sense, but it's also something you're
adding to the system and not something that's there, so if you want to talk about the same game system we're talking about and not just your home version of it, you're going to have to be aware that those aren't the default rules.
Perhaps its a difference of play style, but I'm convinced the way I'm doing it makes sense. Every time you try to show a situation Harry has been in and model it using your method of understanding, know that it would be just as easy for me to do the same thing with my understanding, and it would still be coherent.
Sure it would, FATE is flexible like that. You'd still be adding things. Things that aren't necessarily there and that don't necessarily work for the rest of us.
Thank you for the suggestions, but know them for what they are.