Re: Staying soft.
Musashi was not in the same period or situation. From what I have gathered from my reading on the internet (and I CANNOT be wrong, everything on the internet IS true - lol) martial arts were kind of competing for survival with challenges between schools being very frequent, especially when a new teacher or a new art came to town. I've heard (from the all knowing internet) that there could have been a few hundred schools of jujitsu alive around this time. The number is quite feasable, especially concidering O Sensei was one of Takeda's better students.
But again, I am throwing out what I understand to be the case, anyone who disagrees or has evidence otherwise is welcome to disagree/correct me.