Re: Non-aggressive way to test ability and level of understanding.
The "death grip" some people have used on me to try to "test" my ability to do tai no henko is neither how it would be " on the street" ( where grabbing my wrist in itself would serve no purpose; it only makes sense as an intro to some form of dynamic movement to do something to me) nor martially is it an effective aikido attack because it doesn't connect to my center or affect my structure. A properly "relaxed" grab with intent is an attack on my center AND gives me something to respond to.
Maggie, I also agree with your point. When I'm in class, I'm trying to follow what my instructor is demonstrating AND work on what is my particular issue - I try to be respectful that my partner likely has his own issue and we should not presume to impose our personal training goals or interests on our partners.