I am the first one to say that those who love the energy exchange (I call it catching air) should be left alone to enjoy themselves and not be criticized for it. There is no requirement that they have to be able to fight. The only time issues arise are when they become deluded into thinking any portion of that is real and will work under stress with trained people........
Agreed, IMO, I believe there is some good stuff going on at the subconscious, and even atomic level, with those cooperative types of interactions; it can really make you feel good afterwards (think along qigong lines here
) We do that with certain Aikido techniques simply as an exercise to help with awareness of movement and timing in the interaction - we do not consider it training of a martial skill; it is simply an exercise. There is absolutely nothing wrong with this type of activity as long as everyone is aware of what it really is and does not consider it martially effective.
However, for those that would like to test the effectiveness of their skills and techniques, it is fairly easy (and safe as long as uke has good ukemi and knows when to stop) to actually attack with real intentional grabs and continue the attack until either uke stops nage or nage stops uke - of course, this approach can be tricky with striking attacks. Anyway, the only way to actually know if your skills are martially effective is to take on a real attack - any other type of test, regardless of your style, is simply delusion.