Re: static vs. dynamic waza
I think in many koryu the sempai acts as uke first.
Poor uke waza is one of my soap box issues with aikido because I felt I had a pretty good introduction to good uke waza and I am still reminded by my seniors about bad habits and poor tactics I employ. I think aikido could make leaps and bounds in our training if uke was better prepared. Issues like this thread are fallout from bad uke waza and loose terminology.
The people I respect in aikido could care less whether you attack them or grab their hand statically. It doesn't matter. There is another thread ongoing right now that is talking about kuzushi, or "aiki" that relates directly to this premise.