Re: Stress-testing structure
I'm going to go out on a limb and say that your post isn't what Lee is talking about at all. This just sounds like a list of strategic counters (not that there's anything wrong with it...) but doesn't address the concept of testing structure at all.
I'm still a huge fan of many of the most basic exercises for testing structure. Get into a posture (mabu, twisted mabu, bow stance even mugamae) and have someone put constant building pressure into you to the point of failure. Then do it from different angles, use different mental constructs to find one that works better for you.
From there I like walking mabu or doing something similar with your partner pushing on the chest. You can play with different kinds of connections: are you simply able to overwhelm your partner? Can you "pop" them back? Can you simply walk them across the room so that they feel like there's nothing they can do to stop you even though it doesn't look or feel like you're putting much force into them?
Pushout is still huge, because it creates a dynamic space where you learn to maintain frame and guide it through your intent. Aiki age can be similar, but there seem to be more mechanical tricks you can use with aiki-age, where pushout doesn't give you many crutches to fall back on. Brilliant really.
During waza, we'll often adjust the attack to test different things. I think of how I attack as like a slider on a line, it goes from [super light go with what nage directs aikido style (yuck)] -> [stiffer and forceful but very responsive (still Aikido style, meh)] -> [Big Dumb Muscle (harder to deal with, but generally able to be moved by someone with structure] -> [structure/frame based attack with varying intents (hardest to deal with that I play with regularly)]. We mostly slide back and forth between BDM and Structure/frame based attacks.
Recently we worked on receiving jointlocks through the frame. You could think of it as pushout through a nikyo. Like the push tests, there's a limit to how much you can take and the point is to go to failure (in a safe environment not populated by egomaniacs) to stretch that boundary.
There's more, but that's all I have time for. Honestly it's kind of in everything I/we do on the mat anymore, even in my batto practice.